Peri-articular infiltration in the resource-restrained environment - still a worthwhile adjunct to multimodal analgesia post total knee replacement

ABSTRACT BACKGROUND: Peri-articular infiltrations (PAI) in total knee arthroplasty (TKA) offer effective analgesia, and are cost effective, safe and easy to perform. Currently there is no gold standard technique based on evidence-based medicine; described methods are based on consensus recommendations. The latest literature supports PAI including complex and multiple drug combinations, such as liposomal bupivacaine, ropivacaine and ketorolac, which are not available in all settings. This study aims to prove that a basic PAI technique using widely available and inexpensive agents offers good and effective outcomes in a resource-poor environment METHODS: A double-blind randomised control trial compared the effectiveness of PAI with a simple, widely available anaesthetic solution (bupivacaine and adrenalin) to a normal saline control group. Infiltration volumes were calculated at 1 ml/kg and the infiltration technique followed a specific protocol. Post-operative outcomes included visual analogue scores (VAS), ambulation scores, morphine use, knee range of motion (ROM) and time to discharge RESULTS: Two comparable groups of 26 patients each were included (intervention: 81% female, mean age 64.8±8.8 years vs control: 65% female, mean age 67.0±7.6 years). All pain-related measures favoured the intervention group but failed to reach statistical significance at 24 and 72 hours. Mean VAS scores at 48 hours were significantly lower in the intervention group. (VAS score 3.0±1.6 vs 4.1±1.2, p=0.013). The other parameters measured strongly favoured the intervention group but did not prove to be significant CONCLUSIONS: A volume per kilogram PAI technique making use of widely available, cost-effective agents provides a statistical reduction in VAS scores at 48 hours post TKA. This suggests that in a resource-poor environment PAI is still a valuable addition to the multimodal analgesia pathway in the post-operative management of TKA. Maximum drug doses may show even more promising results, specifically in the first 24 hours post-operatively. Further studies investigating PAI for TKA in resource-restrained environments are indicated Level of evidence: Level 2 Keywords: standardisation peri-articular infiltration, multimodal analgesia, pre-emptive analgesia

Optimising perioperative care for hip and knee arthroplasty in South Africa: a Delphi consensus study

Background

A structured approach to perioperative patient management based on an enhanced recovery pathway protocol facilitates early recovery and reduces morbidity in high income countries. However, in low- and middle-income countries (LMICs), the feasibility of implementing enhanced recovery pathways and its influence on patient outcomes is scarcely investigated. To inform similar practice in LMICs for total hip and knee arthroplasty, it is necessary to identify potential factors for inclusion in such a programme, appropriate for LMICs.

Methods

Applying a Delphi method, 33 stakeholders (13 arthroplasty surgeons, 12 anaesthetists and 8 physiotherapists) from 10 state hospitals representing 4 South African provinces identified and prioritised i) risk factors associated with poor outcomes, ii) perioperative interventions to improve outcomes and iii) patient and clinical outcomes necessary to benchmark practice for patients scheduled for primary elective unilateral total hip and knee arthroplasty.

Results

Thirty of the thirty-three stakeholders completed the 3 months Delphi study. The first round yielded i) 36 suggestions to preoperative risk factors, ii) 14 (preoperative), 18 (intraoperative) and 23 (postoperative) suggestions to best practices for perioperative interventions to improve outcomes and iii) 25 suggestions to important postsurgical outcomes. These items were prioritised by the group in the consecutive rounds and consensus was reached for the top ten priorities for each category.

Conclusion

The consensus derived risk factors, perioperative interventions and important outcomes will inform the development of a structured, perioperative multidisciplinary enhanced patient care protocol for total hip and knee arthroplasty. It is anticipated that this study will provide the construct necessary for developing pragmatic enhanced care pathways aimed at improving patient outcomes after arthroplasty in LMICs.

Exploratory behaviour and novel predator recognition: behavioural correlations across contexts

It was hypothesized that the exploratory behaviour of an individual measured in a novel environment could predict its behaviour in response to a novel predator. This study examined novel predator recognition in the western mosquitofish Gambusia affinis, a species with individual differences in risk-taking, activity and exploration in novel environments. Prey responded with characteristic shoaling and avoidance in response to native predators, but did not show characteristic antipredator behaviour towards novel predators. Furthermore, G. affinis exhibited individual-level behavioural correlations across contexts but only when prey were tested with native predators. This could be the result of native predatory selection on behavioural correlations in the prey species.

Quality improvement in acute stroke: The New York State Stroke Center Designation Project

BACKGROUND

Many hospitals lack the infrastructure required to treat patients with acute stroke. The Brain Attack Coalition (BAC) published guidelines for the establishment of primary stroke centers.

OBJECTIVE

To determine if stroke center designation and selective triage of acute stroke patients improve quality of care.

METHODS

Baseline chart abstraction was performed on all stroke patients admitted to 32 hospitals serving Brooklyn and Queens, NY, from March to May 2002. Hospitals were invited to meet BAC guideline-based criteria. Adherence was verified by on-site visits. After designation, acute stroke patients were selectively triaged. Remeasurement data were collected from August to October 2003.

RESULTS

The authors abstracted 1,598 charts at baseline and 1,442 charts at remeasurement. From baseline to remeasurement, median times decreased for door to physician contact (25 vs 15 minutes, p = 0.001), CT performance for potential tissue plasminogen activator (t-PA) candidates (68 vs 32 minutes, p < 0.001), and t-PA administration (109 vs 98 minutes (p = NS). IV t-PA utilization increased from 2.4 to 5.2% (p < 0.005), select t-PA protocol violations decreased from 11.1 to 7.9% (p = NS), and the stroke unit admission rate increased from 16 to 39% (p < 0.001). In stroke centers (n = 14) vs nondesignated hospitals (n = 18), there were shorter median times from door to physician contact (10 vs 25 minutes, p < 0.001), CT performance for potential t-PA candidates (31 vs 40 minutes, p = NS), and t-PA administration (95 vs 115 minutes, p < 0.05). Stroke centers, compared with nondesignated centers, admitted acute stroke patients to stroke units more often (55.9 vs 10.9%, p < 0.001).

CONCLUSIONS

Stroke center designation and selective triage of acute stroke patients improved the quality of care, including access to timely thrombolytic therapy and stroke units.

rhBMP-2 injected in a calcium phosphate paste (alpha-BSM) accelerates healing in the rabbit ulnar osteotomy model

This study evaluated the ability of recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered in an injectable calcium phosphate carrier (alpha-BSM) to accelerate healing in a rabbit ulna osteotomy model compared to untreated surgical controls. Healing was assessed by radiography, histology and biomechanics. Bilateral mid-ulnar osteotomies were created in 16 skeletally mature rabbits. One limb in each animal was injected with either 0.1 mg rhBMP-2/alpha-BSM (BMP) (N=8) or buffer/alpha-BSM (BSM) (N=8). Contralateral osteotomies served as untreated surgical controls (SXCT). Gamma scintigraphy showed 75%, 45% and 5% of the initial 125I-rhBMP-2 dose was retained at the osteotomy site at 3 h, 1 week and 3 weeks. The biological activity of rhBMP-2 (alkaline phosphatase activity from bioassay) extracted from alpha-BSM incubated in vitro up to 30 days at 37 degrees C was unchanged. Radiographs demonstrated complete bridging of the BMP limbs at 4 weeks whereas none of the BSM or SXCT limbs were bridged. Post-mortem peripheral quantitative computed tomography determined mineralized callus area was 62% greater in BMP limbs compared to SXCT limbs. Torsional stiffness and strength were 63% and 103% greater in BMP limbs compared to SXCT limbs. There was no difference in torsional properties between BSM and SXCT limbs. Failure occurred outside the osteotomy in four out of seven of the BMP limbs. All BSM and SXCT limbs failed through the osteotomy. Histology showed bony bridging of the osteotomy and no residual carrier in the BMP limbs. BSM and SXCT groups showed less mature calluses composed of primarily fibrocartilaginous tissue and immature bone in the osteotomy gap. These data indicate rhBMP-2 delivered in alpha-BSM accelerated healing in a rabbit ulna osteotomy model compared to BSM and SXCT groups.

Recombinant human bone morphogenetic protein-2 enhances osteotomy healing in glucocorticoid-treated rabbits

The objectives of this study were to evaluate the effect of chronic prednisolone treatment on osteotomy healing in rabbits and to determine whether recombinant human bone morphogenetic protein-2 (rhBMP-2) would enhance healing in the presence of chronic glucocorticoid therapy. Forty-nine skeletally mature, male rabbits were injected with either prednisolone (n = 26; 0.35 mg/kg per day, three times a week) or saline (n = 23). After a 6-week pretreatment period, bilateral ulnar osteotomies were created surgically. One osteotomy was treated with rhBMP-2 (0.2 mg/ml of rhBMP-2, 40 microg of rhBMP-2 total) delivered on an absorbable collage sponge (ACS), whereas the contralateral osteotomy remained untreated. Prednisolone or saline treatment was continued until the rabbits were killed either 6 weeks or 8 weeks after creation of the osteotomy. Osteotomy healing was evaluated by radiography, peripheral quantitative computed tomography (pQCT), torsional biomechanics, and undecalcified histology. Because we observed similar responses to both prednisolone and rhBMP-2/ACS treatment in the 6-week and 8-week cohorts, the results from these time points were combined. Serum osteocalcin and vertebral trabecular bone density were lower in the prednisolone-treated rabbits. Prednisolone treatment dramatically inhibited osteotomy healing. In the untreated ulnas, callus area and torsional strength were 25% and 55% less, respectively, in the prednisolone-treated rabbits than in the saline group (p < 0.001 for both). rhBMP-2/ACS enhanced healing in both the prednisolone- and the saline-treated groups, although the effect was larger in the prednisolone-treated rabbits. In the prednisolone-treated rabbits, callus area and torsional strength were 40% and 165% greater (p < 0.001 for both), respectively, in osteotomies treated with rhBMP-2/ACS compared with the contralateral, untreated osteotomies. Histological evaluation confirmed that osteotomy healing was inhibited by prednisolone and accelerated by rhBMP-2/ACS. In summary, a single application of rhBMP-2/ACS counteracted the inhibition of osteotomy healing caused by prednisolone exposure. These results suggest that rhBMP-2/ACS may be a useful treatment for enhancing fracture healing in patients who are undergoing chronic glucocorticoid therapy.

Recombinant human bone morphogenetic protein-2 accelerates healing in a rabbit ulnar osteotomy model

BACKGROUND

Approximately 5% to 20% of fractures have delayed or impaired healing. Therefore, it is desirable to develop new therapies to enhance fracture-healing that can be used in conjunction with traditional treatment methods. The purpose of this study was to evaluate the ability of a single application of recombinant human bone morphogenetic protein-2 to accelerate fracture-healing in a rabbit ulnar osteotomy that heals spontaneously.

METHODS

Bilateral mid-ulnar osteotomies (approximately 0.5 to 1.0 mm wide) were created in seventy-two skeletally mature male rabbits. The limbs were assigned to one of three groups: those treated with an absorbable collagen sponge containing recombinant human bone morphogenetic protein-2, those treated with an absorbable collagen sponge containing buffer, and those left untreated. In the first two groups, an 8 20-mm strip of absorbable collagen sponge containing either 40 g of recombinant human bone morphogenetic protein-2 or buffer only was wrapped around the osteotomy site. The rabbits were killed at two, three, four, or six weeks after surgery. In addition, twenty-four age-matched rabbits were used to provide data on the properties of intact limbs. The retention of recombinant human bone morphogenetic protein-2 at the osteotomy site was determined with scintigraphic imaging of (125)I-labeled recombinant human bone morphogenetic protein-2. After the rabbits were killed, the limbs were scanned with peripheral quantitative computed tomography to assess the area and mineral content of the mineralized callus. The limbs were then tested to failure in torsion, and undecalcified specimens were evaluated histologically.

RESULTS

Gamma scintigraphy of (125)I-recombinant human bone morphogenetic protein-2 showed that 73% +/- 6% (mean and standard deviation) of the administered dose was initially retained at the fracture site. Approximately 37% +/- 10% of the initial dose remained at the site one week after surgery, and 8% +/- 7% remained after two weeks. The mineralized callus area was similar in all groups at two weeks, but it was 20% to 60% greater in the ulnae treated with recombinant human bone morphogenetic protein-2 than in either the ulnae treated with buffer or the untreated ulnae at three, four, and six weeks (p < 0.05). Biomechanical properties were similar in all groups at two weeks, but they were at least 80% greater in the ulnae treated with recombinant human bone morphogenetic protein-2 at three and four weeks than in either the ulnae treated with buffer (p < 0.005) or the untreated ulnae (p < 0.01). By four weeks, the biomechanical properties of the ulnae treated with recombinant human bone morphogenetic protein-2 were equivalent to those of the intact ulnae, whereas the biomechanical properties of both the ulnae treated with buffer and the untreated ulnae had reached only approximately 45% of those of the intact ulnae. At six weeks, the biomechanical properties were similar in all groups and were equivalent to those of the intact ulnae. The callus geometry and biomechanical properties of the ulnae treated with buffer were equivalent to those of the untreated ulnae at all time-points.

CONCLUSIONS AND CLINICAL RELEVANCE

These findings indicate that treatment with an absorbable collagen sponge containing recombinant human bone morphogenetic protein-2 enhances healing of a long-bone osteotomy that heals spontaneously. Specifically, osteotomies treated with recombinant human bone morphogenetic protein-2 healed 33% faster than osteotomies left untreated. The results of this study provide a rationale for testing the ability of recombinant human bone morphogenetic protein-2 to accelerate healing in patients with fractures requiring open surgical management.

Interactions between estrogen, tamoxifen, octylphenol, and two polychlorinated biphenyls in murine splenocytes

Prior exposure of cultured murine splenocytes to 17beta-estradiol (E) protects them from the membrane disrupting effects of the xenoestrogen 4-tert-octylphenol (OP). Using splenocytes isolated from male Balb/c mice, we tested whether (a) the xenoestrogen, 2', 3', 4', 5'-tetrachloro-4-biphenylol (PCB-OH), or the polychlorinated biphenyl, 3, 3', 4, 4'-tetrachlorobiphenyl (PCB 77), which displays both estrogenic and anti-estrogenic actions, would compromise the membrane integrity of the cells and (b) E or tamoxifen (TX), another ligand for the E receptor, would protect the membranes of cells exposed to the agents. We also examined possible interactions between OP, PCB-OH, and PCB 77 on the cells. Splenocytes were cultured for 24 hr. Concentrations of OP (10(-5)-10(-9) M), PCB-OH (10(-6)-10(-16) M), or PCB 77 (10(-8)-10(-12) M) significantly compromised the membrane integrity of the cultured splenocytes in a dose response manner. Concentrations of E as high as 10(-5) M or TX as high as 10(-7) M were without effect. Incubation of splenocytes in medium containing E or TX at 10(-7) M for 2 hr prior to the subsequent addition of either OP, PCB-OH or PCB 77 (final concentrations of 10(-7), 10(-7), or 10(-8) M, respectively) blocked the membrane disrupting effects. Incubation of splenocytes in medium containing 10(-7) M E starting 2 hr after the addition of OP or PCB 77 or incubation of splenocytes in medium containing 10(-7) M TX starting 2 hr after the addition of OP or PCB-OH did not block the damaging effects of OP, PCB 77, or PCB-OH on the cell membranes. No interactions were observed when various combinations of OP, PCB-OH, or PCB 77 were used. These data suggest that: (a) TX acts like E in this system, (b) a prior response of splenocytes to E or TX can protect them from the potential cytotoxic effects of OP, PCB-OH, or PCB 77; and, (c) OP, PCB-OH, and PCB 77 were not additive in their actions.

Toxic effects of octylphenol on cultured rat spermatogenic cells and Sertoli cells

Alkylphenols, including the estrogenic 4-tert-octylphenol (OP), are environmental pollutants. Because administration of OP to adult male rats impairs spermatogenesis and OP has been shown to be toxic to aquatic animals and to mammalian splenocytes in vitro, we studied whether OP exerts direct toxic effects on cultured spermatogenic cells and Sertoli cells isolated from male rats. Cell viability was assessed with a Live/Dead Eukolight viability/cytotoxicity kit. Culture of mixed spermatogenic cells from adult rats with 10(-8) M OP or Sertoli cells from 19- to 21-day-old rats with 10(-12) M OP, but not with 0.08% EtOH (vehicle) or 10(-6) M 17beta-estradiol (E2) or dexamethasone (DEX), significantly decreased the percentage of viable cells after 24 h of treatment. None of the treatments significantly altered total cell number. Flow cytometric analyses of spermatogenic cells revealed that exposure to 10(-4) or 10(-6) M OP yielded abnormal relative ploidy classes. Four hours of treatment with 10(-6) M OP, but not with 10(-6) M E2 or DEX, caused significant chromatin condensation in Sertoli cells as observed with acridine orange staining. The decreased percentage of viable cells after 24 h of exposure to 10(-6) M OP remained when Sertoli cells were cultured in Ca2+-free medium. Sertoli cells contained nuclei of reduced size and labeled 3'-OH DNA ends as detected by microscopic analyses when the cells had been incubated for 24 h with 10(-6) M OP but not with vehicle or 10(-6) M E2 or DEX. The results demonstrate that OP, but not E2 or DEX, is directly toxic to cultured rat spermatogenic cells and Sertoli cells and suggest that this toxic effect in Sertoli cells is exerted through Ca2+-independent apoptosis.

Disruption of rat estrous cyclicity by the environmental estrogen 4-tert-octylphenol

4-tert-Octylphenol (OP) is a prevalent environmental pollutant which binds to estrogen receptors and exerts estrogenic actions in vitro. The effects of OP in vivo on mammalian female reproduction are not known. We investigated whether (i) exposure of neonatal rats to OP interfered with the onset of vaginal opening or their ability to have regular estrous cycles as adults and (ii) exposure of adult rats to OP interfered with estrous cyclicity and ovulation. Injection of 1 mg OP in corn oil sc on the day after birth did not affect the day of vaginal opening. However, 9 of 11 OP-treated rats were in persistent vaginal estrus when examined at three months after birth compared with 0 of 9 corn oil-injected controls, which cycled regularly. Ten of eleven neonatal rats injected with 1.7 mg of the estrogenic pesticide methoxychlor also were in persistent estrus at 3 months after birth, and all 10 neonatal rats injected with 1 mg of 2,4,5-trichlorophenol, which is apparently nonestrogenic, cycled regularly. Injection of 20 or 40 mg OP in corn oil vehicle sc three times weekly into previously untreated adult cyclic rats caused persistent estrus in 2 of 6 and 16 of 21 rats, respectively. Injections were continued for three more weeks in 5 of the 16 rats rendered persistent estrus by the 40 mg OP treatment. These rats remained in persistent estrus for the additional 3-week period. The other 11 persistent estrous rats in the 40 mg treatment group started to cycle regularly within 5-7 days after the last injection. Unlike pentobarbital, injection of OP into cyclic rats during the afternoon of proestrus did not block ovulation. These results provide strong evidence that OP acts like estrogen in vivo in both neonatal and adult female rats to exert effects that block reproductive cyclicity.

Chronic administration of the environmental pollutant 4-tert-octylphenol to adult male rats interferes with the secretion of luteinizing hormone, follicle-stimulating hormone, prolactin, and testosterone

4-Tert-octylphenol (OP) is a prevalent environmental pollutant that has been shown to exert both toxic and estrogenic effects on mammalian cells. The effects of OP on the reproductive system of adult male vertebrates are virtually unknown. In the present study, we investigated the effects of chronic exposure to OP on reproductive hormone secretion in the adult male rat and compared the results qualitatively with those observed in other male rats treated chronically with estrogen. We injected corn oil vehicle or OP (20 or 80 mg) or estradiol valerate (EV; 0.8 or 8 microg) in oil s.c. into 2-mo-old male rats thrice weekly for either 1 or 2 mo. The 80-mg dosage of OP and one or both dosages of EV had the following effects: decreased anterior pituitary gland (APG) and serum LH and FSH concentrations; increased APG and serum prolactin (PRL) concentrations; increased APG/body weight ratios; decreased serum testosterone concentrations; decreased hematocrit; and decreased food consumption and body weight gain. To evaluate the response of the hypothalamus-APG to gonadal removal, we orchidectomized some of the rats after the end of treatment and decapitated them 3 wk later. In orchidectomized controls, serum LH and FSH concentrations rose markedly and serum PRL concentrations decreased. Similar changes were seen in orchidectomized rats treated previously with 20 or 80 mg OP. Moreover, there were no differences in mean serum LH, FSH, or PRL concentrations between controls and rats treated previously with either dosage of OP at 3 wk after orchidectomy. The results demonstrate that chronic administration of OP to adult male rats can adversely affect the secretion of reproductive hormones and strongly suggest that OP exerts these effects by acting like an estrogen. The opposite changes in LH, FSH, and PRL secretion observed after cessation of treatment with OP and orchidectomy suggest that chronic treatment with OP under the conditions of the present study did not result in any significant permanent deleterious effects on gonadotrophs or lactotrophs or the hypothalamic neurons controlling the secretion of the gonadotropins or PRL.

Chronic administration of 4-tert-octylphenol to adult male rats causes shrinkage of the testes and male accessory sex organs, disrupts spermatogenesis, and increases the incidence of sperm deformities

The environmental toxicant 4-tert-octylphenol (OP) has been shown to exert estrogenic effects on mammalian cells in culture. Recent findings from our laboratories demonstrate clearly that OP administration disrupts reproductive hormone secretion in the adult male rat, quite likely as a result of estrogenic action. In the present study, we investigated the impact of these or other OP-induced changes on male reproductive tissues. Adult male rats were injected with OP (20 or 80 mg) or estradiol valerate (EV; 0.8 or 8 microg) s.c. in oil three times a week for either 1 or 2 mo. We found that an 80-mg dosage of OP for 2 mo or an 8-microg dosage of EV for 1 or 2 mo greatly reduced sperm numbers and adversely influenced the sizes, weights, and histological structures of the testes, epididymides, ventral prostate glands, seminal vesicles, and coagulating glands. The 80-mg dosage of OP for 1 mo reduced epididymal tubule size to a lesser extent than after 2 mo of treatment. Otherwise, treatment with 80 mg OP for 1 mo, 20 mg OP for 1 or 2 mo, or 0.8 microg EV for 1 mo had little or no effect on the histology of the tissues we examined. Additional evaluation of sperm morphology revealed marked increases in the proportions of head and tail abnormalities from animals that had received 80 mg of OP or 8 microg of EV for 1 mo and 20 mg of OP for 2 mo. The head abnormalities consisted mainly of pin heads, detached heads, and the absence of hooks, while tail abnormalities included mainly broken, coiled, and bent tails. Our results clearly demonstrate that OP can severely reduce the size and/or function of all of the male gametogenic and accessory reproductive organs studied. Moreover, the similarity of these cell and tissue changes between rats treated with OP and those treated with EV further suggests that OP may exert its action in an estrogenic-like manner.

Estrogen can protect splenocytes from the toxic effects of the environmental pollutant 4-tert-octylphenol

Four-tert-octylphenol (OP), an environmental pollutant, exerts apoptotic effects on cultured mouse splenocytes. Although OP binds to estrogen receptors, these apoptotic effects are not exerted by 17 beta-estradiol (E). It remained possible that OP might bind to estrogen receptors and subsequently exert apoptotic effects not exerted by E after it binds to the same receptors. It also remained possible that E-primed splenocytes might respond to OP differently than splenocytes not exposed to E. Thus, we investigated OP and E interactions on the viability of mouse splenocytes in culture. The total number of splenocytes (cells stained and not stained with trypan blue) was not altered or altered slightly after incubation with any agent for 24 h. Incubation of splenocytes in medium containing 5 x 10(-5) or 5 x 10(-7) M OP decreased the percentage of viable cells by only approx 47% and 25%, respectively. The addition of 0.8 x 10(-5) to 0.8 x 10(-9) M E to cultures was without effect or decreased the percentage of viable cells by only approx 5%. The addition of these concentrations of E simultaneously with or at 2 h after the addition of 5 x 10(-5) M or 5 x 10(-7) M OP to cultures did not interfere with the OP-induced decreases in cell viability. By contrast, incubation of splenocytes in medium containing E for 2 h prior to the subsequent addition of either dose of OP blocked the OP-induced decreases in cell viability in a dose-response manner. There was a marked reduction in the percentage of viable cells (70%) when splenocytes were incubated with 0.5 x 10(-5) M dexamethasone. The addition of 0.8 x 10(-5) M E at 2 h prior to the addition of dexamethasone did not prevent the decreased cell viability. Incubation of cells in medium with 0.8 x 10(-5) M testosterone caused a small decrease in splenocyte viability similar to that observed with E. However, unlike E, the addition of testosterone at 2 h prior to the addition of 5 x 10(-5) M OP did not prevent the OP-induced decrease in cell viability. These data suggest the presence of estrogen receptors in some splenocytes. They also suggest that if OP binds to these estrogen receptors or other receptors in the absence or initial presence of E, the resulting effect is toxic to the cells. By contrast, exposure of splenocytes to E prior to their exposure to OP can prevent the toxicity of OP.

Toxic effects of octylphenol on cultured rat and murine splenocytes

Alkylphenol polyethoxylates and alkylphenols, such as 4-tertoctylphenol (OP), are environmental contaminants. Because these compounds are toxic to aquatic animals, we studied the effects of OP on splenocytes removed from male Fischer 344 rats or male Balb/c mice and cultured in vitro. Cell viability was assessed by trypan blue exclusion after 5 or 27 hr of culture. Culture with 0.08% ETOH (vehicle) or any dose of OP did not alter total cell number or the percentage of viable cells after 5 hr. Culture of cells with two different alkylphenol polyethoxylates for 5 hr resulted in the loss of all cells. The percentages of viable rat or mouse cells after 27 hr of culture were decreased significantly by 10(-12) M OP or greater concentrations. The actions of OP, dexamethasone (DEX), and 17 beta-estradiol on rat splenocytes were compared. Dexamethasone was more toxic than OP after 24 hr of culture; 17 beta-estradiol was not toxic. Dexamethasone and OP, but not 17 beta-estradiol, caused significant nuclear condensation after 3 hr of culture (acridine orange staining) or 4 hr of culture (propidium iodide staining). The toxicity of 10(-6) M OP, but not that of 10(-6) M DEX, was eliminated when mouse splenocytes were cultured in Ca2+ -free medium. Significantly more mouse splenocytes containing free 3'-OH DNA ends were detected by activated cell sorter analyses when the cells had been incubated for 4 hr with 10(-4) or 10(-6) M OP or 10(-6) M DEX. The results of these studies demonstrate that OP is toxic to cultured rat and mouse splenocytes and suggest that this toxic effect is exerted, at least partially, through Ca2+-dependent apoptosis.

Adenohypophysial allografts releasing prolactin decrease prolactin mRNA concentration in the host hamster's adenohypophysis in situ

The inhibitory effects of pituitary allografts on the prolactin (PRL)-secretory system are presumed to be consequences of the unabated release of PRL by the allografts. In the present studies we used pituitary allografts in the Golden Syrian hamster to address the following questions: (a) Do allografts of adult adenohypophysial tissue which elevate serum PRL levels decrease the concentration of PRL mRNA in the host's adenohypophysis? (b) Is this effect shared by allografts of neonatal hypophysial tissue or neonatal muscle tissue which do not elevate serum PRL levels? (c) Do any of these types of allograft alter growth hormone mRNA in the host's adenohypophysis? Prolactin mRNA concentration, but not growth hormone mRNA concentration, was decreased in the adenohypophyses in situ in the hosts bearing adult adenohypophysial allografts in which serum PRL levels were elevated. In contrast, serum PRL in hosts with neonatal hypophysial or muscle allografts were not elevated and PRL mRNA levels in the adenohypophysis in situ were not decreased when compared to the levels measured in hamsters with sham transplants. Prolactin mRNA levels in hosts with neonatal muscle allografts were not different from levels in hosts with neonatal hypophysial allografts but were increased when compared to the levels measured in hamsters with sham transplants. There were no differences in PRL concentration in the adenohypophyses in situ between any of the groups. Also, PRL concentrations in neonatal hypophysial allografts were similar to those in adult adenohypophysial allografts. To our knowledge these observations are the first demonstrating that short-loop feed-back of PRL includes a decrease in PRL mRNA concentration. The observations also support the working hypothesis that PRL and not another pituitary factor exerts the negative feedback.

Changes in percentages of adenohypophysial gonadotrophs associated with the sex-specific, selective increase in serum follicle-stimulating hormone concentration in the juvenile female hamster

In normal hamsters, we investigated whether the sex-specific, selective increase in serum FSH concentration in the juvenile female was associated with sex-specific changes in the percentages of adenohypophysial gonadotrophs. Serum LH concentrations did not rise between Day 4 and Day 19 in either sex and did not differ significantly between the sexes on Days 4, 7, 12, 14, and 19 after birth. Serum FSH concentrations were about 2-fold higher on Days 7, 12, and 14 than on Days 4 or 19 in males. In females, serum FSH rose markedly between Days 4 and 7, declined slightly by Day 12, rose to peak levels by Day 14, and declined slightly by Day 19 to levels not different from those seen on Day 7. Body weights rose between Days 4 and 19 and were similar in both sexes. There were no sex differences in pituitary gland weights, which rose between Days 4 and 12 and did not increase significantly further by Day 19. On Day 0, the percentages of immunoreactive LH and FSH cells were about 6 and 1%, respectively, in both sexes. These percentages increased progressively between Days 0 and 7 and between Days 7 and 14. On Day 7, but not on Day 14, the percentages of LH and FSH cells were greater in females than in males. There were more LH than FSH cells in males on Days 0, 7 and 14, and in females on Day 0 but not on Day 7 or 14. Matching of 10 FSH cells per gland with LH cells in serial sections of each of 30 glands showed FSH immunoreactivity to occur only in cells staining for LH. In hypophysectomized-gonadectomized adult hamster hosts with allografts of neonatal pituitary glands beneath the renal capsule, we investigated whether these sex-specific changes in the percentage of cells might be predetermined by the time of birth or dependent on sex differences in the internal environment existing in the postnatal hamster. Groups consisted of male donors-male hosts, male donors-female hosts, female donors-female hosts, and female donors-male hosts. The percentages of LH cells in allografts in all four groups increased from Days 0 to 7 and from Days 7 to 14. Percentages of LH cells on Day 14 in all four groups were not different from those in age-matched male or female adenohypophyses in situ. In contrast, the mean percentages of FSH cells were low (about 1-3%) on Days 0, 7, and 14 in all four groups. In other males hosts, administration of a low dose of LHRH for 7 days did not alter the percentage of LH cells in male allografts but increased the percentage of FSH cells to approach that observed in age-matched male adenohypophyses in situ. Administration of a larger dose of LHRH for 7 days to other male hosts with male allografts increased the percentages of LH and FSH cells to percentages not different from those in age-matched female adenohypophyses in situ. Matching of 10 FSH cells/allograft with LH cells in serial sections of each of 58 allografts showed FSH immunoreactivity to occur only in cells staining for LH. The results of experiments conducted on normal hamsters demonstrate that more marked increases in the percentages of adenohypophysial LH cells and FSH cells occur in females than in males in association with the onset of the selective increase in serum FSH levels in females. The results of experiments employing allografts suggest that the greater increase in LH and FSH cells in females is due to sex differences in the internal environment existing in the postnatal hamster, which can be accounted for by differences in LHRH secretion, rather than to inherent differences between female and male adenohypophyses at the time of birth. We conclude that the greater increases in gonadotrophs observed in female hamster pups on Day 7 after birth and the accompanying sex-specific, selective elevation in serum FSH concentration are probably due to sex differences in LHRH secretion during the juvenile period.

Neuropeptide Y and luteinizing hormone releasing hormone synergize to stimulate the development of cellular follicle-stimulating hormone in the hamster adenohypophysis

Luteinizing hormone releasing hormone (LHRH) stimulates the development of cellular FSH immunoreactivity in the perinatal hamster adenohypophysis. Because neuropeptide Y (NPY) can act directly on rat adenohypophysial cells to stimulate FSH and LH release and potentiate the stimulatory effect of LHRH on FSH and LH release, we investigated the effects of NPY alone and in combination with a low, ineffective dose of LHRH on inducing cellular FSH immunoreactivity in the neonatal hamster adenohypophysis. Neonatal female pituitary glands were grafted beneath the right renal capsules of hypophysectomized-ovariectomized adult hamster hosts with a catheter implanted in the external jugular vein. After treatment, hosts were decapitated and graft tissue was stained for FSH and LH immunoreactivity. The mean percentage of adenohypophysial cells that stained for FSH was low (2.8%) in grafts in hosts infused continuously with heparinized saline vehicle for 7 days. In other hosts, peptides were pulsed through the catheter every 12 h for 7 days. The mean percentage of FSH cells also was low after pulsing 6 ng LHRH or 2 micrograms NPY but increased substantially when the two peptides were pulsed simultaneously. No differences in the mean percentage of LH cells existed between any of the groups. The results demonstrate that NPY and LHRH can synergize to induce cellular FSH immunoreactivity in the neonatal female hamster.

Induction of cellular follicle-stimulating hormone in the hamster adenohypophysis requires intermittent stimulation by luteinizing hormone releasing hormone

We investigated the effectiveness of continuous vs intermittent LHRH stimulation of the neonatal female anterior pituitary gland on inducing cellular FSH immunoreactivity in the Golden Syrian hamster. Neonatal female pituitary glands were grafted beneath the right renal capsules of hypophysectomized-ovariectomized adult hosts with a catheter implanted in the external jugular vein. In experiment 1, vehicle or LHRH (6 ng/h) was infused continuously or LHRH was pulsed at 1 h (6 ng) or 12 h (72 ng) intervals through the catheters for 8 days. Hamsters were decapitated for collection of trunk blood shortly after the end of treatment, and grafts were prepared for immunocytochemical staining for LH and FSH. Anterior pituitary glands removed from neonatal (day 1) and day 9 female pups also were stained for LH and FSH. The mean percentage of adenohypophysial cells staining for LH increased from 11% in neonatal pups to mean percentages (24-28%) that were similar in day 9 pups and in all groups with grafts. The mean percentage of adenohypophysial cells staining for FSH increased from 1% in neonatal pups to percentages (16-21%) that were similar in day 9 pups and in grafts in hosts administered 6 or 72 ng LHRH pulses. By contrast, the mean percentage of FSH cells did not increase in grafts in hosts administered vehicle or LHRH by continuous infusion. Serum LH concentration was low in hosts given vehicle or LHRH by continuous infusion but elevated in hosts given 72 ng LHRH pulses and in all but one host given 6 ng LHRH pulses.(ABSTRACT TRUNCATED AT 250 WORDS)

Estrogen alters the effects of neuropeptide-Y on luteinizing hormone and follicle-stimulating hormone release in female rats at the level of the anterior pituitary gland

In recent years, several studies have shown that neuropeptide-Y (NPY) is involved in the control of LH secretion. We determined the effects of estrogen on NPY-induced LH and FSH release in the absence or presence of LH-releasing hormone (LHRH) at the level of the anterior pituitary gland (APG). Adult female rats were ovariectomized. Fifteen to 20 days later, they were given a blank or estrogen-filled capsule subdermally and killed 17-19 h later. APG cells were isolated and cultured for 3 days in medium containing 12.5% rat serum collected at death from the same rats used to make the respective APG cell pools. The cells were then challenged for 3 h with vehicle, NPY (10(-12)-10(-6) M), LHRH (10(-9)-10(-6) M), or combinations of NPY (10(-9)-10(-7) M) and LHRH (10(-9) M). LHRH stimulated LH and FSH release from nonestrogen and estrogen-primed cells. NPY at 6.7 x 10(-8)-10(-6) M increased (P < 0.05) LH release and at 10(-6) M increased (P < 0.05) FSH release from estrogen-primed cells, but was without effect on nonestrogen-primed cells. In contrast, NPY at 10(-9)-10(-7) M potentiated the action of LHRH (10(-9) M) to increase the release of LH and FSH from nonestrogen-primed cells, but was without potentiating effects in cultures of estrogen-primed cells. The results demonstrate that 1) NPY can release LH and FSH by a direct action on estrogen-primed APG cells; and 2) NPY can potentiate the action of LHRH to increase the release of LH and FSH by a direct action on nonestrogen-primed APG cells.

Effects of injection of anti-luteinizing hormone (LH)-releasing hormone serum and anti-gonadotropin-releasing hormone-associated peptide serum into neonatal rats on LH and follicle-stimulating hormone cells

Relatively little is known regarding the potential importance of LHRH and of gonadotropin-releasing hormone-associated peptide (GAP) on the postnatal development of gonadotrophs. We investigated the effects of administration of anti (A)-LHRH serum or A-GAP serum to neonatal rats on the development of LH and FSH immunoreactivity in anterior pituitary gland (APG) cells. Serum (sheep non-immune [NSS], sheep A-LHRH, sheep A-LHRH/GAP [which bound LHRH and GAP], rabbit non-immune [NRS], or rabbit A-GAP) was injected s.c. into neonatal female and male rats on Days 1 and 3 or Days 1, 3, 5, and 7 after birth. Pups were killed on Day 5 or 9, two days after the last injection. The percentages of APG cells immunoreactive for LH or FSH increased from Day 1 to Day 5 and did not change between Days 5 and 9 in female pups treated with NSS or NRS. There was a trend for the percentages of LH and FSH cells to increase from Day 1 to Days 5 and 9 in male pups treated with NSS or NRS, but the increases were not statistically significant. In both females and males, treatment with antisera that recognized LHRH reduced the percentage of FSH cells on Day 5 and the percentages of LH and FSH cells on Day 9. Treatment with A-GAP was without effect in both sexes. There were similar percentages of LH and FSH cells in females and a lower percentage of FSH than of LH cells in males in the Day 5 and 9 controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunocytochemical staining of neuropeptide Y (NPY) in the insular lobe of the monkey: a light microscopic study

Neuropeptide Y (NPY) has been detected immunocytochemically in cerebral cortex and subcortical white matter of the primate frontal, parietal, temporal, and occipital lobes. Because little is known about NPY in the primate insular lobe and because peptides play an important role in normal neuronal functioning and alterations in brain peptides are associated with certain neurological diseases, we studied the presence, distribution, and structural characteristics of NPY-immunostained elements at the light microscopic level in the insula of Macaca fascicularis. We used free-floating sections, rabbit anti-porcine NPY serum, and the avidin and biotinylated peroxidase complex technique. Neuropeptide Y-immunostained neurons were demonstrated in layers II, III, and V/VI, and in the adjoining subcortical white matter. Immunostaining was localized to neuronal somata, neuronal processes, and a delicate plexus in the neuropil. The majority of NPY-immunostained neurons were non-pyramidal, had round somata 10-20 microns in major transverse diameter, and two or three neuronal processes. Computer-aided quantitative analysis of the length, breadth, and area of NPY-stained neurons was performed. Our findings are consistent with observations by others on the presence, laminar distribution, and structural characteristics of NPY-immunostained elements at the light microscopic level in other cerebral lobes of non-human primates.

Familial ovarian cancer. A report of 658 families from the Gilda Radner Familial Ovarian Cancer Registry 1981-1991

BACKGROUND

Because of the small number of cases (five) reported between 1929 and 1969 and a significant increase reported in the decade of the 1970s, the Familial Ovarian Cancer Registry was established in 1981 to study the occurrence of familial ovarian cancer in the United States.

METHODS

Any woman (with or without ovarian cancer herself) who contacted the Registry and demonstrated a familial history of ovarian cancer was added to the Registry as an index case.

RESULTS

From 1981 through May 31, 1991, 658 families for a total of 1568 cases of familial ovarian cancer were accessioned into the Registry. Of the 219 mothers and 251 daughters with familial ovarian cancer, the mean (58.5 years) and median (57.0 years) age at diagnosis of the mothers was significantly older than the mean (49.8 years) and median (49.0 years) ages of their daughters with ovarian cancer. Significantly more index cases without ovarian cancer had used oral contraceptives as compared to index cases with ovarian cancer (P < 0.001). Significantly more index cases with ovarian cancer used other estrogens as compared to index cases without ovarian cancer (P < 0.001). The Registry cases exhibited a higher proportion of serous adenocarcinoma, poorly differentiated adenocarcinoma, borderline carcinoma, and gonadoblastoma as compared to the 1978 SEER data. Mother and a minimum of one daughter was the most common relationship and was represented in 49.5% of the families with familial ovarian cancer. Sister-sister relationships were the second most frequent and accounted for 38.5% of the 658 families.

CONCLUSIONS

Familial ovarian cancer occurs most frequently in mother-daughter relationships followed by sister-sister and appears to be an autosomal dominant inheritance with variable penetrance.

Gonadotropin-releasing hormone-induced accumulation of follicle-stimulating hormone beta-subunit messenger ribonucleic acid in adenohypophysial cells developing in an ectopic position

We investigated the influence of LHRH on the accumulation of FSH beta messenger RNA (mRNA) in anterior pituitary glands removed from hamster pups less than 36 h old and transplanted beneath the renal capsules of adult male hamsters (hosts). Three experiments were performed in which some hosts were injected sc with LHRH (1 microgram/injection) and others were injected with vehicle. Injections were begun in the afternoon of the day of transplantation (day 1) and were given at 0800 and 1700 h for 6 days and at 0800 h on the eighth day. An additional experiment was performed in which adult male hamsters not bearing allografts were injected with the same regimen of LHRH or vehicle. The hamsters were decapitated on the eighth day of the study, 2 h after the last injection. The allografts, adenohypophyses of the hosts, adenohypophyses of hamsters without allografts, and adenohypophyses of normal adult male rats were removed and frozen on dry ice immediately. Additionally, adenohypophyses were collected from hamster pups less than 36 h old and 8 and 15 days of age. Total RNAs from some pooled specimens were electrophoresed on a formaldehyde-agarose gel. After transfer to Nytran, the RNAs were hybridized sequentially to complementary DNAs for rat FSH beta and hamster beta-actin. The rat FSH beta complementary DNA probe hybridized to a single RNA (approximately 1.7 Kb) in rat adenohypophyses. It predominantly hybridized to RNA of approximately 1.7 Kb from hamster adenohypophyses. Sometimes it hybridized to RNAs ranging in size from 0.5 Kb to 1.7 kb. The hybridization signals for all samples obtained from dot blot analyses were quantitated and normalized to the signals for beta-actin. The hybridization signals obtained from adenohypophyses of hamsters of different ages increased from 36 h of age to adulthood. The hybridization signal obtained from adenohypophyses of hamsters less than 36 h old (the same age as the donor hamsters) was similar to the hybridization signal obtained from allografts in vehicle-treated hamsters. The relative levels of FSH beta mRNA in allografts of LHRH-treated hosts were: 1) greater than the relative levels in adenohypophyses of hamsters less than 36 h old (P less than 0.05) and in allografts in vehicle-treated hamsters (P less than 0.05), 2) greater than the relative levels in adenohypophyses of 8-day-old hamsters (P less than 0.05), and 3) not different compared to the relative levels in adenohypophyses of 15-day-old hamsters and adult male hamsters.(ABSTRACT TRUNCATED AT 400 WORDS)

Intraperitoneal injection of chloral hydrate causes intra-abdominal adhesions and unilateral testicular atrophy in golden Syrian hamsters

We investigated the reason for the high mortality we had observed in hypophysectomized-orchidectomized Golden Syrian hamsters that were anesthetized with intraperitoneal (i.p.) injections of chloral hydrate (CH). Intact male Golden Syrian hamsters were injected intraperitoneally with 0.1cc/100g BW of a 35% solution of CH, a 35% solution of sodium chloride, or double-distilled water. Equal numbers of hamsters in each group were injected on the right or left side of the abdomen. Within 10 days, 35% of the CH-injected hamsters were dead or had to be euthanized. Autopsy revealed severe peritonitis and adynamic ileus. CH-injected hamsters that survived gained weight at a rate similar to that of the controls. All surviving hamsters were killed 18 days after the injections. Among the surviving CH-injected hamsters, 84.6% had intra-abdominal adhesions, 61.5% had unilateral testicular atrophy, and 53.8% had a yellowish necrotic mass in the epididymal fat pad (EFP). All the lesions occurred on the side that was injected. The atrophied testes had been rendered cryptorchid due to involvement with intra-abdominal adhesions. In the water-treated controls, there were no abnormalities; whereas, in the saline controls, 75% had a mass in the EFP. Histology of the EFP mass was similar in hamsters injected with CH or hypertonic saline and suggested a diagnosis of fat necrosis. The results suggest that the mortality, the intra-abdominal adhesions, and the unilateral cryptorchidism were caused by a single i.p. injection of CH, but the fat necrosis in the EFP was probably caused by high concentrations of salt. The results further suggest that high concentrations of CH should not be injected intraperitoneally for anesthesia in chronic studies, particularly of the male reproductive system.

Basal luteinizing hormone and follicle-stimulating hormone release rates as a function of time after castration in female and male rats

We investigated the potential importance of the basal follicle-stimulating hormone (FSH) and luteinizing hormone (LH) release rates in causing the acute and chronic elevations in serum FSH and LH concentrations which occur after ovariectomy (OVX) and orchidectomy (ORCH) of rats. Diestrous day 1 female and male rats were decapitated or castrated and killed 2, 4 or 8 h or 1, 2, 7, 21 or 35 days later. In females, the weight of the anterior pituitary gland (APG) did not change. Serum FSH rose within 4 h and then progressively higher until 35 days after OVX. These increases were paralleled nearly perfectly with increases in APG FSH concentration which was first elevated at 1 day after OVX and in the basal FSH release rate (measured in vitro) which was first elevated at 4 h after OVX. Serum LH levels rose by 7 days after OVX and then more dramatically thereafter. These increases were associated with increased APG LH concentrations. The pronounced increases in serum LH levels between 7 and 35 days after OVX were associated with marked increases in the basal LH release rate. In males, APG weight was increased at 21 and 35 days after ORCH. Serum FSH levels were elevated at 1 day after ORCH and continued to rise until 21 days after ORCH. APG FSH concentration was decreased at 2 and 7 days and increased at 35 days after ORCH. The basal FSH release rate per milligram APG did not change significantly after ORCH. Serum LH levels were elevated at 8 h after ORCH. They rose further by 1 day and then further between 7 and 21 days after ORCH. APG LH concentration and the basal LH release rate per milligram APG were elevated at 21 and 35 days after ORCH. The results suggest that changes in basal FSH and LH release are (1) involved to a major extent in causing the post-OVX rise in serum FSH concentration during the first 5 weeks after OVX and in serum LH concentration between 7 and 35 days after OVX, (2) not involved in causing the post-ORCH rises in serum FSH and LH concentrations during the 1 week after ORCH, and (3) involved to some extent in causing the elevations in serum FSH and LH concentrations observed at 3 and 5 weeks after ORCH. The results also indicate that (1) increases in the basal gonadotropin release rates per milligram APG after castration may be coupled in some way with increased synthesis of gonadotropin, and (2) increases in the basal LH release rate per milligram APG can occur independently of an increase in the basal FSH release rate per milligram APG.

The response of splenic lymphocytes removed from hypophysectomized-orchidectomized hamsters to phytohemagglutinin correlates with somatic growth but not with circulating prolactin levels

To examine the relationship between PRL and the mitogenic capacity of lymphocytes, we studied the relationships among circulating PRL levels, somatic growth, and the response of splenic lymphocytes to the mitogen phytohemagglutinin (PHA) in hamsters. In the first experiment, no differences were observed in the PHA responses of lymphocytes removed from intact or hypophysectomized-orchidectomized hamsters. No relationships were observed between circulating PRL levels and either the PHA responses or somatic growth. However, significant positive correlations were observed between the somatic growth of intact or hypophysectomized-orchidectomized hamsters and the PHA responses (r = 0.741; P less than 0.01 for intact hamsters; r = 0.642; P less than 0.01 for hypophysectomized-orchidectomized hamsters). In three subsequent experiments we tested the effects of placing muscle or hypophysial allografts in hypophysectomized-orchidectomized hamsters on somatic growth, the PHA responses, and circulating PRL levels. Neither type of allograft altered the somatic growth of hypophysectomized-orchidectomized hamsters. The hypophysial allografts did elevate serum PRL levels. In all experiments the responses of splenic lymphocytes to PHA showed a significant positive correlation with somatic growth, but not with serum PRL levels. These results minimize a role of PRL in this particular lymphocyte response. The results suggest that a strong correlation exists between mechanisms responsible for somatic growth in hypophysectomized-orchidectomized hamsters and the immune status, as determined by the response to PHA, of the animals. This relationship also may exist in intact hamsters.

Blockade of the selective increase in serum follicle-stimulating hormone concentration in immature female rats and its effects on ovarian follicular development

We investigated whether administration of monosodium L-glutamate (MSG) to neonatal female rats would block the selective increase in serum follicle-stimulating hormone (FSH) concentration in immature rats in an attempt to provide a model in which to study the importance of the selective FSH rise on ovarian follicular development. In two separate experiments, s.c. injections of MSG (4 mg/g BW) on Days 1, 3, 5, 7 and 9 after birth blocked the selective increase in serum FSH concentration observed on Days 7 and 15 without blocking basal FSH secretion. Serum luteinizing hormone (LH) levels were unaffected in the first experiment and changed little in the second. MSG-treated rats had smaller ovaries on Days 15 and 23. The ovaries of MSG-treated rats on Day 15 showed decreased follicular growth as evidenced by a decrease in the number and percentage of follicles with diameters greater than 50 microns, in the number of follicles with greater than 1 layer of granulosa cells, and in the number of follicles beyond the primary stage of follicular development. These differences between MSG-treated rats and controls all but disappeared by Day 23. The results demonstrate that neonatal administration of MSG blocks the selective increase in serum FSH concentration in immature female rats and suggest that this selective increase in serum FSH levels plays a role in the normal acceleration of ovarian follicular development but is not needed for the development of preovulatory follicles by the sixth week after birth.

Luteinizing hormone (LH)-releasing hormone: chronic effects on LH and follicle-stimulating hormone cells and secretion in adult male rats

We investigated whether chronic administration of LHRH to normal adult rats could increase the percentages of anterior pituitary gland (APG) cells that contain immunoreactive LH and/or FSH and gonadotropin secretion. Vehicle or 1 microgram LHRH was injected sc twice daily for 6 days, and rats were decapitated 16 h after the last injection. Treatment with LHRH caused nearly a doubling in the numerical density of LH and FSH cells and in the percentage of APG cells that contained LH or FSH. It also caused a shift in the gonadotroph population from LH and LH/FSH cells to LH/FSH cells. It did not change the mean size of gonadotrophs or APG weight. These changes at the light microscopic level were not accompanied by any apparent changes in LH cells at the ultrastructural level. However, they were accompanied by an approximate doubling of the basal serum LH and FSH concentrations, an increase in the APG FSH concentration, and an increase in the basal FSH release rate (measured in vitro). The results indicate that exogenous LHRH can be administered to increase numbers of gonadotrophs in the APG, synthesis of FSH in gonadotrophs, and basal serum LH and FSH concentrations.

Luteinizing hormone (LH)-releasing hormone: effects on maintenance of immunoreactive follicle-stimulating hormone and LH in adenohypophysial cells

We investigated the importance of LHRH on the maintenance of FSH and LH immunoreactivity in gonadotrophs. Hypophysectomized orchidectomized hamsters (hosts) each received an allograft of a 7-week-old male hamster pituitary gland beneath their right renal capsule. Starting 6 days after transplantation, hosts were injected sc, twice daily with 1 micrograms LHRH or vehicle for 16 days. Twelve hosts in each group were killed by decapitation 16 h after the last injection. Allografts from six of the hamsters in each group and pituitary glands in situ from 10-week-old normal males were prepared for histological examination. Sections of tissue were stained for FSH or LH and with hematoxylin. Allografts from the remaining hamsters were homogenized to measure FSH and LH concentrations. In allografts from the vehicle-treated hosts, 22.8% of adenohypophysial cells stained for LH, while only 16.9% stained for FSH. In allografts from LHRH-treated hosts, 22.6% and 23.8% of the adenohypophyses cells stained for LH and FSH, respectively. Adenohypophyses that developed for the same length of time in situ had 24.8% and 24.1% of the cells staining for LH and FSH, respectively. Matching of some of the FSH and LH cells in serial flip-flopped sections of tissue from all hamsters revealed that many if not all gonadotrophs contained LH. LH- and FSH-containing cells in allografts were similar in size and shape, but were smaller and more circular in profile than those observed in situ. Treatment of hosts with LHRH did not alter gonadotroph size or shape, but it did reduce allograft LH concentration and elevate the serum FSH concentration compared to that in the vehicle-treated hamsters. These results suggest that in the hamster LHRH 1) plays a major role in maintaining FSH immunoreactivity in adenohypophysial tissue, 2) does not play a role in maintaining numbers of immunoreactive LH cells in adult adenohypophysial tissue, and 3) functions to maintain FSH synthesis at least in part in cells that contain LH.

Effects of corticotrophin-releasing hormone on corticotrophs in anterior pituitary gland allografts in hypophysectomized, orchidectomized hamsters

We investigated the effects of corticotrophin-releasing hormone (CRH) on the percentage of anterior pituitary gland (APG) cells which are corticotrophs as well as the size and shape of corticotrophs. Pituitary glands were removed from 7-week-old male hamsters and placed beneath the renal capsules of hamsters that had been hypophysectomized and orchidectomized 3 weeks previously. Beginning 6 days after each host had received a single allograft, each was injected subcutaneously twice daily with 4 micrograms CRH or vehicle for 16 days. Six hosts in each group were decapitated 16 h after the last injection. Sections of anterior pituitary tissue were stained for ACTH and with hematoxylin. The percentage of corticotrophs among APG cells was greater in allografts exposed to exogenous CRH (approximately 20%) than in allografts exposed to vehicle (approximately 15%). Exposure to exogenous CRH increased the cross-sectional area of corticotroph cells in allografts to values greater than those measured for corticotrophs in allografts exposed to vehicle, without altering the shape of cells. Results of subsequent studies suggested that hamsters with allografts injected with vehicle do not release ACTH and that exogenous CRH causes an abrupt release of ACTH from allografts. These results indicate that CRH releases ACTH from ectopic corticotrophs and that administration of CRH can increase corticotroph size and the percentage of APG cells that are corticotrophs.

Luteinizing hormone (LH)-releasing hormone: effects of induction of LH, follicle-stimulating hormone, and prolactin cell differentiation

We investigated the influence of LHRH on the differentiation of gonadotrophs and lactotrophs in fetal pituitary glands transplanted beneath the renal capsules of adult hypophysectomized-orchidectomized hamsters (hosts). Hypophyses were removed from hamster fetuses at a gestational age of 14 days. Some of these were immediately fixed in Bouin's solution, and others were transplanted into the hosts. The hosts were injected sc twice daily with 1 microgram LHRH or vehicle for 16 days. Six hosts in each group were killed by decapitation 16 h after the last injection. Six 14-day-old normal male hamsters (age-matched to correspond to the age of the allografts at the time of the hosts' decapitation) also were decapitated. Sections of hypophyses in situ from fetal hamsters, from 14-day-old controls, and from allografts in each group were stained for LH, FSH, or PRL and with hematoxylin. No PRL-containing cells and very few LH or FSH cells (less than 0.025% of the adenohypophysial cell population) were observed in fetal pituitary glands. In allografts from the vehicle-treated hosts, 21.1% of adenohypophysial cells contained LH, but only 1.8% contained FSH. In allografts from LHRH-treated hosts, 28.0% and 22.9% of the adenohypophysial cells contained LH and FSH, respectively. Adenohypophyses that developed for the same length of time in situ had smaller percentages of adenohypophysial cells containing LH (23.8%) and FSH (15.5%) than the LHRH-treated group. LH-containing cells in allografts in the vehicle-treated hamsters, but not in the LHRH-treated animals, were reduced in size compared to those measured in situ. The number of lactotrophs in all allografted tissue was markedly reduced compared to that of lactotrophs in situ, and injection of LHRH into hamsters with allografts did not alter the percentage of adenohypophysial cells that were lactotrophs. These results suggest that in the hamster LHRH 1) plays an important role in stimulating the formation of immunoreactive FSH in the pituitary gland, 2) can increase the number of gonadotrophs that develop during the neonatal period, and 3) plays a role in controlling the size of gonadotrophs during development. The results also suggest that the development of lactotroph cell number requires close proximity to the hypothalamus and/or exposure to a neonatal environment. We found no evidence to support the view that LHRH, LH, or FSH stimulates immunoreactive lactotroph differentiation.

Basal gonadotropin hormone release rates during the period of selective follicle-stimulating hormone release in the juvenile female rat

There are situations in which adult female rats release increased amounts of follicle-stimulating hormone (FSH) independent of increased luteinizing hormone (LH) release. This results from, at least in part, a selective increase in the basal FSH release rate. We investigated whether an increase in the basal FSH release rate is contributory to the rise in serum FSH levels which occurs independent of a rise in serum LH levels in the immature female rat. Rats had high serum FSH concentrations on days 7 and 15 after birth, low serum FSH levels on day 23, and low serum LH levels on all three days. In contrast, anterior pituitary gland (APG) FSH and LH concentrations and contents increased from day 7 to day 15 and the contents increased further from day 15 to day 23. Similarly, basal FSH and LH release rates per mg APG or per APG, as assessed by measurement of FSH and LH released into culture medium containing APG(s) from different aged rats, increased from day 7 to day 15 but did not increase further between days 15 and 23. The results indicate that unlike situations observed to date in adult female rats, a mechanism(s) other than an increase in the basal FSH release rate is involved in selective FSH release in the immature female rat.

Effects of growth hormone-releasing hormone on somatotrophs in anterior pituitary gland allografts in hypophysectomized, orchidectomized hamsters

We investigated the influences of growth hormone-releasing hormone (GHRH) on the percentage, size, and shape of somatotrophs in ectopic anterior pituitary tissue. Entire pituitary glands removed from 7-week-old male hamsters were placed beneath the renal capsules of 12-week-old hamsters that had been hypophysectomized and castrated 3 weeks previously. Beginning 6 days after each host had received a single allograft, each was injected subcutaneously twice daily with 4 micrograms GHRH in 100 microliter of vehicle or 100 microliter of vehicle for 16 days. Six hosts in each group were killed by decapitation on day 17, 16 h after the last injection. Nine normal male hamsters were also decapitated and their pituitary glands were removed. Sections of anterior pituitary tissue were stained for GH and with hematoxylin. The percentage of anterior pituitary cells that stained for growth hormone was similar in the 3 groups. In contrast, somatotrophs in grafts had a smaller mean cross-sectional area than those observed in glands in situ. This effect was reversed by GHRH. Analysis of the shape of somatotrophs in both groups of grafts disclosed that they were less circular in cross-section than those in glands in situ. The results suggest that GHRH may not play a role in maintaining the percentage of somatotrophs among anterior pituitary cells, but that it does play a role in maintaining their size.

An immunohistochemical study of adenohypophyseal cells containing follicle-stimulating hormone and luteinizing hormone during the phase of selective follicle-stimulating hormone release in postnatal female rats

Serum concentration of follicle-stimulating hormone (FSH) in the juvenile female rat increases independently from that of luteinizing hormone (LH). The objective of this study was to determine whether this increase in serum FSH is accompanied by a proliferation of FSH-cells greater than the proliferation of LH-cells. Thus, we measured circulating FSH and LH in female rats on days 3, 10, 13, 17, and 20, calculated the percentages of adenohypophyseal cells that contained FSH or LH on days 3, 10, and 20, and determined whether cells containing only FSH existed on day 10. Serum FSH concentrations on days 10 and 13 were significantly greater than those on days 3, 17, or 20. No differences existed in serum LH concentrations. Cells containing FSH or LH were distributed throughout the entire adenohypophyses of 3, 10, and 20-day-old females. Clusters of these cells were observed in the ventral regions of adenohypophyses of 3-day-old females. The percentages of adenohypophyseal cells containing FSH increased significantly from approximately 9% in 3-day-old rats to approximately 17% in 10-day-old rats and then decreased to approximately 14% in 20-day-old animals. At all ages the percentages of adenohypophyseal cells containing FSH were similar to the percentages of cells containing LH. At 10 days of age, all cells containing FSH also contained LH and all cells containing LH also contained FSH. These data suggest that the increase in serum FSH in the juvenile female rat is associated with an increase in the percentage of adenohypophyseal cells containing FSH and that at this time all cells containing FSH also contain LH.

Effects of hypothalamic neurohormones on prolactin release from pituitary allografts in the hamster

Recent reports indicate that luteinizing hormone-releasing hormone (LHRH) releases prolactin (PRL) under some circumstances. We examined the chronic effects of LHRH, growth hormone-releasing hormone (GHRH), and corticotrophin-releasing hormone (CRH) on the release of PRL, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) by pituitary allografts in hypophysectomized, orchidectomized hamsters. Entire pituitary glands removed from 7-week-old-male Golden Syrian hamsters were placed under the renal capsule of hypophysectomized, orchidectomized 12-week-old hamsters. Beginning 6 days postgrafting, hamsters were injected subcutaneously twice daily with 1 microgram LHRH, 4 micrograms GHRH, or 4 micrograms CRH in 100 microliter of vehicle for 16 days. Six hosts from each of the four groups were decapitated on Day 17, 16 hr after the last injection. Prolactin, LH, and FSH were measured in serum collected from the trunk blood. Treatment with LHRH significantly elevated serum PRL levels above those measured in the other three groups, which were all similar to one another. Serum LH levels in hosts treated with vehicle were elevated above those measured in the other three groups. Serum FSH levels in hosts treated with LHRH were greater than FSH levels in any of the other three groups. These results indicate that chronic treatment with LHRH can stimulate PRL and FSH release by ectopic pituitary cells in the hamster.

Effects of neuropeptide Y on LH, FSH and TSH release in male rats

These experiments were undertaken to investigate the effects of systemically administered neuropeptide Y (NPY) on gonadotropin secretion in the intact male rat and to determine whether the effects observed might be mediated by a direct action of NPY alone on the anterior pituitary gland (APG). Subcutaneous administration of 10 micrograms of NPY caused a greater than 2-fold increase in serum luteinizing hormone (LH) concentration at 15 min after injection but was without effect on serum follicle-stimulating hormone (FSH) or thyrotropin-stimulating hormone (TSH) levels. The addition of NPY (final concentrations of 10(-8) to 10(-11) M) or the structurally similar neuropeptide, rat pancreatic polypeptide, to culture medium containing hemi-APG did not alter the release of LH, FSH, or TSH. The results indicate that systemically administered NPY can elevate serum LH concentration in intact male rats. This effect does not appear to be due to NPY acting alone at the level of the APG.

Monosodium L-glutamate administration: effects on gonadotrophin secretion, gonadotrophs and mammotrophs in prepubertal female rats

We have studied gonadotrophin secretion and immunocytochemically stained gonadotrophs and mammotrophs in 35-day-old female rats which had been treated with monosodium glutamate (MSG) as neonates. We also compared our morphometric data in the saline-treated controls with those we have previously obtained in normal adult female rats. The size of the anterior pituitary glands was reduced but the serum levels, the pituitary gland concentrations and contents, and the in-vitro basal release rates of LH and FSH were not significantly altered by MSG treatment. The size of the LH and FSH cells was reduced by MSG administration, but the volume and numerical densities of LH and FSH cells, and the percentage of LH and FSH cells in the pars distalis were not affected. The results suggest that in spite of the smaller size of LH and FSH cells and of the anterior pituitary glands in the MSG-treated rats, the cells contain normal amounts of hormone and the basal LH and FSH secretion rates of the glands are not significantly depressed, contributing to the maintenance of normal serum gonadotrophin concentrations. The volume density of prolactin cells was not increased by MSG treatment. The volume density of gonadotrophs and the percentage of cells which are gonadotrophs in anterior pituitary glands of prepubertal female rats were greater than those in adult female rats, but the reverse was true for the volume density of prolactin cells, suggesting a reciprocal relationship between the relative numbers of gonadotrophs and mammotrophs in prepubertal and adult female rats.

Monosodium glutamate and pituitary gland luteinizing hormone (LH) release in response to LH-releasing hormone: an in vitro study

We studied whether an increase in the basal LH release rate and/or the anterior pituitary gland (APG) LH response to LHRH is involved in maintaining normal or near-normal serum LH levels in monosodium L-glutamate (MSG)-treated rats which have small APGs for their body weight. Female rats were injected with MSG (4 mg/g BW) or saline on days 1, 3, 5, 7, and 9 after birth (day of birth = 0). At 8-9 weeks of age, saline-treated and MSG-treated rats were ovariectomized, and 7 days later, they were decapitated. Trunk blood was collected from 18 controls and 19 MSG-treated rats, and serum LH concentrations were measured by RIA. APGs were bisected and each hemi-APG was placed in culture medium for a 30-min preincubation period, followed by two 30-min incubation periods during which water or 10 or 30 ng LHRH were added to the medium. Despite the fact that the APGs of the MSG-treated rats were half the size of those of the saline-treated rats, the serum LH levels in the 2 groups were not different. Basal LH release rates (the response to water) and LHRH-induced LH release per mg APG were increased in MSG-treated rats. Calculation of the basal LH release rates and LHRH-induced LH release on the basis of the entire weights of the APGs showed no differences between the MSG-treated rats and the controls. In 6 additional control and 6 additional MSG-treated rats, the APG LH concentration was measured and was not different between the 2 groups. The results suggest that increases in both the basal LH release rate per mg APG and the amount of LH released per mg APG in response to LHRH are of importance in the maintenance of normal or near-normal serum LH concentrations in MSG-treated rats with small APGs.

Effects of neonatal administration of monosodium glutamate on somatotrophs and growth hormone secretion in prepubertal male and female rats

Female and male rats were injected with monosodium L-glutamate (MSG; 4 mg/g BW) or 0.9% saline as neonates and then decapitated on days 35 and 40 of life, respectively. Trunk blood was collected for RIA of serum GH. Anterior pituitary glands (APGs) were bisected. One half was assayed for GH. The other half was placed in culture medium to study the basal GH release rate. Pituitary sections from additional rats were stained for GH, and morphometric analyses were performed on the GH cells. Treatment with MSG lowered serum GH levels and gland GH content in female but not in male rats. MSG did not alter the gland GH concentration or the basal GH release rate whether expressed per mg APG or per entire gland in either sex. The mean cross-sectional area of GH cells was reduced in either sex of MSG-treated rats. The numerical density of GH cells and the percentage of GH cells in APGs were similar in saline- and MSG-treated rats of either sex. The volume density of GH cells was lower in MSG-treated male rats only. The results suggest that in prepubertal rats which had been given MSG as neonates there is a sex difference in mean serum GH concentration and APG GH content, GH cell size is reduced in both sexes, and the individual GH cells contain normal amounts of GH in spite of their smaller size.

A decrease in thymus-mediated immune responses as a result of treatment of neonatal rats with glutamate

We investigated whether administration of monosodium 1-glutamate (MSG) to neonatal rats would disrupt immune responses in intact and orchidectomized adult male rats. Neonatal male rats were treated with saline or MSG which causes severe endocrine abnormalities. Half of each group of animals were orchidectomized as adults and killed one week later along with intact rats. MSG treatment resulted in suppressed serum LH levels in intact rats. Thymus weight and spleen cellularity in intact animals were not affected by MSG treatment, but thymus weight increased within one week after orchidectomy in both saline- and MSG-treated groups. In intact rats, lymphocyte stimulation by the T cell specific mitogens (concanavalin A or phytohemagglutinin) or the B cell specific mitogen (lipopolysaccharide) was unaffected by prior treatment with MSG. However, MSG treatment blocked the decrease attributable to orchidectomy in concanavalin A and phytohemagglutinin stimulation of lymphocyte blastogenesis. The results suggest that administration of MSG to neonatal male rats can alter some immune responses in the adult animal.

Administration of monosodium glutamate to neonatal male rats: alterations in the gonadotrophs and in gonadotrophin secretion

We have studied the effect of administration of L-monosodium glutamate (MSG) to neonatal rats on gonadotroph morphology and gonadotrophin secretion in the prepubertal male rat. Rats were injected with MSG (4 mg/g body weight) or with 0.1 ml saline/10 g body weight on days 1, 3, 5, 7 and 9 of life (day of birth = day 0) and were used for experiment on day 40. Trunk blood was collected from 8 saline- and 9 MSG-injected rats for assay of serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations. One-half of the anterior pituitary gland was assayed for LH and FSH concentrations and the other half was placed in culture medium for a 30-min preincubation and then placed in fresh medium for a 2-hour incubation (basal LH and FSH release). An additional 4 rats in each group were killed and the pituitary glands were prepared for histological examination and immunocytochemical staining of LH and FSH cells and morphometric examination of these cells at the light microscopic level. The morphometric analyses were compared with those performed previously by us on adult male rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Pars distalis cell quantification in normal adult male and female rats

We analysed cell types in the pars distalis of normal young adult male and female rats with respect to their percentages and the relative volumes they occupy. In male rats the percentages of the cell types were: prolactin 49.80, GH 22.67, LH 5.04, FSH 4.22, ACTH 2.93 and TSH 2.09. The volume densities were: prolactin 20.48, GH 20.95, LH 7.34, FSH 6.73, ACTH 3.75 and TSH 3.19. In female rats the percentages of the cell types were: prolactin 52.40, GH 20.30, LH 5.89, FSH 4.06, ACTH 2.53, TSH 2.40 and the volume densities were: prolactin 28.09, GH 20.86, LH 8.11, FSH 5.46, ACTH 3.49 and TSH 2.91. The percentages of pars distalis cells which did not stain with the antisera to the six classical hormones were 17.47 in male and 16.48 in female rats. The results suggest that (1) in both sexes the number (N) of prolactin cells greater than N of GH cells greater than N of gonadotrophs greater than N of TSH or ACTH cells, (2) the percentage of each cell type was similar in both sexes, (3) the volume density (Vv) of prolactin cells was greater than the Vv of GH cells in female but not in male rats and in both sexes the Vv of GH cells greater than the Vv of gonadotrophs greater than the Vv of TSH or ACTH cells, (4) in both sexes the volume (V) of prolactin cells less than the V of GH cells less than the V of gonadotrophs, the V of TSH cells or the V of ACTH cells, (5) the V of prolactin cells was greater in female than in male rats and (6) approximately 17% of the cells in the pars distalis of both sexes did not contain 'immunoreactive' prolactin, GH, LH, FSH, TSH or ACTH.