Neurohypophyseal hormones protect against pentylenetetrazole-induced seizures in zebrafish: role of oxytocin-like and V1a-like receptor

Oxytocin (OT) and arginine-vasopressin (AVP) are involved in the physiological response to different stressors like the occurrence of seizures which is regarded as a severe stress factor. Zebrafish (Danio rerio) is recently featured as a model of epilepsy but the role of neurohypophyseal hormones on this teleost is still unknown. We attempted to determine whether non-mammalian homologues like isotocin (IT) and vasotocin (AVT) affected pentylenetetrazole (PTZ)-induced seizures in adult zebrafish in comparison with OT/AVP. The mechanism was studied using the most selective OT and AVP receptor antagonists. Zebrafish were injected i.m. with increasing doses (0.1-40 ng/kg) of the neuropeptides 10 min before PTZ exposure. DesGly-NH2-d(CH2)5-[D-Tyr2,Thr4]OVT (desglyDTyrOVT) for OT receptor and SR49059 for V1a subtype receptor, were injected together with each agonist 20 min before PTZ exposure. All the peptides significantly decreased the number of seizures, increased the mean latency time to the first seizure and decreased lethality. This protective effect led to a dose-response curve following a U-shaped form. IT was approximately 40 times more active than OT while AVT was 20 times more potent than AVP in reducing the number of seizures. DesglyDTyrOVT was more effective in antagonizing OT/IT, while SR49059 mainly blocked AVP/AVT-induced protection against PTZ-induced seizures. The present findings provide direct evidence of an important involvement of IT/OT and AVP/AVT as anticonvulsant agents against PTZ-induced seizures with a receptor-mediated mechanism in zebrafish. These data reinforce zebrafish as an emerging experimental model to study and identify new antiepileptic drugs.

[A clinical study of pituitrin versus norepinephrine in the treatment of patients with septic shock]

OBJECTIVE

To investigate whether pituitrin can lower 28-day mortality as compared with treatment with norepinephrine (NE) in patients with septic shock.

METHODS

Randomized, controlled, open-label trial was conducted. One hundred and thirty-nine septic shock patients with dopamine requirements exceeding 5 μg×kg(-1)×min(-1) were divided at random into two groups as the study group and control group. All patients enrolled were treated by the same treatment principle and measures. In patients of study group injection of pituitrin 0.017-0.042 U/min (1.0- 2.5 U/h) was given, and if hemodynamics was still unstable, catecholamines was added to obtain the target blood pressure; while in the control group catecholamines was given to maintain stability of hemodynamics.

RESULTS

Among 139 patients enrolled in the study, 66 composed of the clinical study group and 73 in the control group. The main principle of the treatment in the two groups was similar. There was no significant difference in overall 28-day mortality rate between study group and control group (40.9% vs. 46.6%, P > 0.05). In patients whose acute physiology and chronic health evaluation II ( APACHE II ) score was less than 25, the mortality of study group was significantly lower than that of control group [10.3% (3/29) vs. 35.7% (10/28), P < 0.05]. The length of stay in intensive care unit [ICU, days: 5(3,8) vs. 5(3,8)], and duration of mechanical ventilation [days: 4.0 (2.8, 6.0) vs. 4.0 (2.0, 5.0)] were similar in two groups (both P > 0.05). The dosage of NE (μg/min: 7.99 ± 5.02 vs. 10.12 ± 5.12) and heart rate (beat/min: 93.27 ± 7.84 vs. 108.45 ± 12.31) were significantly lower in study group compared with that of control group (both P < 0.05). Serum creatinine and lactate levels in the two groups were similar at baseline, and creatinine [μmol/L: 87.5 (62.8, 157.0) vs. 76.0 (52.5, 117.0)] and lactate level (mmol/L: 3.72 ± 2.47 vs. 3.53 ± 1.86) were still similar in two groups 24 hours later (all P > 0.05). The rate of use of glucocorticoid (43.9% vs. 31.5%) and heparin in small dosage (42.4% vs. 41.1%) had no significant difference between two groups (both P > 0.05).

CONCLUSIONS

Combined use of pituitrin in patients with septic shock can reduce the dosage of catecholamines, and decrease the heart rate. Although it can not lower the overall mortality of septic shock, among patients with less severity whose APACHE II score lower than 25, low-dose pituitrin in conjunction with catecholamine vasopressors can reduce 28-day mortality .

[Treatment of septic shock in children with low dose pituitrin: report of 24 cases]

OBJECTIVE

To explore the clinical effect of low dose pituitrin in children with septic shock.

METHODS

A total of 48 pediatric cases with septic shock, in whom 6 hours, conventional treatment could not reverse shock from January 2008 to December 2010, were selected for this study. The patients were divided into two groups randomly (completely random design) (control group 24, remedial group 24). The conventional treatment included antibiotics/fluid resuscitation/correcting acid-base imbalance, glucocorticoid, organ (heart/lung) support, dopamine 1 - 15 µg/(kg·min) and norepinephrine 0.5 - 2 µg/(kg·min) pumped in continuously in the control group. In initial 6 hours the same treatment was given to the remedial group, while low dose pituitrin (0.01 - 0.03 U/min) was pumped additionally during the rest of time. The therapeutic effect on correcting shock was evaluated in both groups.

RESULTS

The total effective rate was 76.2% in the remedial group and 40.0% in the control group; the mortality was 33.3% and 60% respectively. The difference between both groups was significant (P = 0.025).

CONCLUSION

Low dose pituitrin could improve the clinical effect significantly in children with septic shock in whom 6 hours conventional treatment failed to correct shock, shorten the total periods of treatment, and decrease mortality.

[Optimization of PNS/TGCO components effect on experimental Qi stagnation and blood stasis type of coronary heart disease with increase-decrease baseline geometric proportion design method]

OBJECTIVE

Preliminary exploration of Panax notoginseng saponins (PNS) and total saponins from Cornus officinalis (TGCO) components treatment and characteristics of Qi stagnation and blood stasis type of coronary heart disease.

METHODS

With increase-decrease baseline geometric proportion design method to Optimization of PNS/TGCO components, through observing different proportions effective components effect on mice with pituitrin-induced acute myocardial ischemia and the time of hypoxia tolerance.

RESULTS

Prescriptions 1, 2, 3 and Xuesaitong groups had a certain degree of improvement the role of myocardial ischemia and prescriptions 4, 5, 6, compared with the control group with no significant changes; Prescriptions 3, 4, 5, 6 had a certain role in anti-anoxia in mice, prescriptions 1, 2 and Xuesaitong group, together with the control group with no significant changes.

CONCLUSION

Prescription 3 has some effect on improving the role of myocardial ischemia and has a certain role in anti-anoxia. It's the best ratio of PNS/TGCO components for the treatment of Qi stagnation and blood stasis type of coronary heart disease.

[Effect of small doses of pituitrin on electrocardiography of ischemia in the experiment]

A new type of reaction to the myocardial ischemia was established in chronic experiments in conscious dogs. It consists in some changes of local myocardial activity and, consequently, in constant or transient normalization of ECG. Pharmacological stabilization of this process augments myocardial resistance to ischemia 40-50 times and more. The role of small doses of pituitrin in this reaction was established.

[The sequelae of transient myocardial ischemia in chronic experiments]

Reversible short-term and local myocardial ischemia in non-anaesthetized dogs involved a functional (if changing the activity of CPK) and morphologic aftereffect. At the same time it is possible to find some mechanisms of compensation (in chronic experiment).

[Lipid peroxidation in vasopressin-induced pulmonary edema and hyperbaric oxygenation therapy]

Experiments in 150 albino rats have revealed that hyperbaric oxygenation (303.98 kPa) causes no decrease in pulmonary tissue hyperhydration and its blood filling induced by pituitrin administration. Hyperbaric oxygen therapy enhances pulmonary tissue peroxidation of lipids, without modifying them in blood. Application of lipid peroxidation inhibitors to prevention of pulmonary edema fails to affect pulmonary hydration and blood filling, which does not rule out the possibility of using them as protective agents against the toxic effects of oxygen in myocardial infarction which may be complicated by acute pulmonary edema.

[Effect of pituitrin or phentolamine alone or in combination on WHVP and systemic hemodynamics in patients with liver cirrhosis]

We observed the effect of pituitrin and phentolamine alone or in combination on wedged hepatic venous pressure (WHVP) and systemic hemodynamics in 28 patients with cirrhosis. The results showed that either of these drugs used separately could lead to reduction in WHVP, each of them could also cause by-effects on systemic hemodynamics. When pituitrin in combination with phentolamine was administered, no change could be found in inferior vena cava pressure, mean arterial pressure, pulse rate and cardiac index. This suggested that pituitrin in combination with phentolamine could not only efficaciously decrease WHVP, but also counteract side effects on systemic hemodynamics of each other and improve hepatic microcirculation. Our study provided evidence for the usefulness of the combination of the two drugs in controlling bleeding from esophagus varices.

[Effect of phentolamine in combination with pituitrin on the hepatic and systemic hemodynamics]

This experimental study was aimed at the effect of phentolamine used separately or in combination with pituitrin on hepatic and systemic hemodynamics in cirrhotic portal hypertensive dogs. The results showed that either of these drugs used separately could lead to reduction of portal venous pressure. Each of the drugs could also cause by-effect on systemic hemodynamics, or reduce hepatic blood flow. When phentolamine was used in combination with pituitrin no side effect was found in hepatic and systemic hemodynamics. It was suggested that phentolamine used in combination with pituitrin could efficiently decrease portal hypertension and counteract the side-effects. It would be useful in treatment of bleeding from esophageal variceal rupture in cirrhotic patients with portal hypertension.

Ultralow doses of vasopressin in the management of diabetes insipidus

Management of postoperative diabetes insipidus (DI) frequently requires intermittent treatment with multiple subcutaneous injections of pituitrin or vasopressin, in doses averaging 20 IU/24 h. Use of a syringe pump for a continuous infusion of ultralow doses of pituitrin produced uniform, constant, and sustained reduction of urinary output, thus facilitating regular fluid replacement. Twelve patients with postoperative DI received iv pituitrin at a dose of 1.6 +/- 0.26 mIU/kg X h (1 to 2 IU/24 h). The antidiuretic effect began at the third hour of treatment, peaked by the sixth hour (diuresis of 37 ml/h, specific gravity of 1.018 +/- 0.002), and was sustained throughout infusion. Polyuria recurred 3 h after the infusion was discontinued; this rapid reversibility is highly advantageous when excessive fluid intake causes overhydration. Pressor effects were not observed during the treatment period.

A comparison of grooming behavior potencies of neurohypophyseal nonapeptides

We have previously demonstrated that intracerebroventricular (ICV) administration of oxytocin (OXY) enhanced grooming behaviors in male and female rats at a 1 microgram dose. In the present study female rats were injected ICV with 1 microgram OXY or equimolar doses of other peptides. At this dose arginine-vasopressin (AVP), arginine-vasotocin (AVT) and lysine-vasopressin (LVP), as well as alpha-MSH, were as effective as OXY in increasing grooming behavior. At equimolar doses, ACTH1-10, tocinoic acid (the ring structure of OXY) and Pro-Leu-Gly-NH2 (the tail structure of OXY) had no significant effect on grooming behavior. The potency of AVP and AVT was determined across a 0.05-5 microgram dose range. Grooming scores increased in an apparent linear manner across a similar OXY dose range. Both AVP and AVT, however, manifested an inverted U grooming response curve. Maximum grooming scores resulted from a 0.1 microgram dose of AVT or a 0.5 microgram AVP dose. Analyses of the aspects of grooming separately found that nonapeptides OXY, AVP and AVT all elevated body grooming, washing, and scratching. Because AVT and AVP administration resulted in grooming scores significantly higher than OXY at lower doses, we concluded that the CNS is more sensitive to the effects of AVT and AVP on grooming behavior than OXY.

Mediastinal and retroperitoneal fibrosis with fibrotic pulmonary nodules: a case report

We report a patient with a long history of pan-hypopituitarism treated with pituitary snuff who developed superior mediastinal fibrosis involving the visceral pericardium, retroperitoneal fibrosis, and a peculiar widespread nodular fibrosis of the lungs.

Action of posterior pituitary neuropeptides on the nigrostriatal dopaminergic system

The effect of vasopressin, oxytocin and the C-terminal tripeptide of oxytocin, prolyl-leucyl-glycinamide (PLG), were tested on rotational behavior, following unilateral 6-OHDA-enduced lesion of the dopaminergic cell bodies in the substantia nigra. Intraventricular injection of lysine8-vasopressin, oxytocin or PLG caused ipsilateral (towards the lesioned side) rotation, as did peripheral administration of amphetamine. Direct local microinjection of the peptides into the substantia nigra on the intact side was without effect. The data suggest that posterior pituitary neuropeptides (vasopressin and oxytocin) caused presynaptic activation of the nigrostriatal dopaminergic terminals.

The physiologic properties and therapeutic potential of coherin

Coherin, a peptide isolated from the bovine neurohypophysis, has been shown to be an effective therapeutic agent in post-gastric surgery physiologic obstruction and regional ileitis. Of twenty-four patients with post-gastric surgery physiologic obstruction, coherin relieved symptoms in twenty-three, a 96 per cent efficacy rate. The efficacy of coherin with ileitis was based on the fact that ten of twenty-seven patients treated have required coherin on a continuing basis to stay functional. These patients have requested coherin treatment for an average of five years each, and have each on multiple occasions tried to discontinue coherin treatment with prompt return of symptoms and cessation of symptoms when coherin was reinstituted. All of the ileitis patients had previously failed to respond to standard and usual medical treatment.

Selective arterial infusion of vasoconstrictors for control of traumatic splenic hemorrhage

The spleen of each of 20 mongrel dogs was traumatized by creating a wedge laceration, and selective arterial infusion was then performed with vasopressin in four dogs, pituitrin in eight, and epinephrine in eight. Infusion therapy with vasoconstrictors controlled the splenic hemorrhage in 19 of 20 dogs. The 15 dogs surviving the experimental period of four to eight weeks showed well-healed scars at the sites of lacerations. Three dogs had small contracted spleens as a result of massive infarction. The results of this experiment indicate that splenic hemorrhage in the experimental dogs can be controlled by selective infusion of pituitrin or vasopressin, but is more effectively controlled with epinephrine.

Long-term results in the treatment of regional ileitis with coherin

Nineteen patients with severe symptoms of ileitis, not responsive to other forms of therapy, have been treated with coherin, a peptide isolated from bovine posterior pituitary glands. This study encompasses observations over a total of 50-patient years. tcoherin has proven efficacious by three criteria: As a result of coherin treatment those patients receiving steroids could either eliminate them or reduce the dosage to safe levels. A significant number of patients whose symptoms have been controlled by coherin have demonstrated their therapeutic dependence on coherin for relief of symptoms by multiple unsuccessful attempts to discontinue treatment over a long period of time. Diarrhea, in patients with ileitis symptoms, is effectively controlled by coherin therapy on a long-term basis.

[Influence of hypertensive substances on the kallikrein-kinin system of the blood]

It is shown that following a one-time intravenous administration to rats of ethyron, epinephrine and pituitrin (in doses causing hypertension) the amount of the blood plasma kininogen is more than halved with concurrently increasing caseinolysis. A two-day long introduction of these substances activates prekallicrein and brings down the level of the kallicrein inhibitors, whereas a 10 and 20-day coursewise administration of these compounds intensifies the synthesis of some components in the kallicrein-kinine system.

A sensitive hydroosmotic toad bladder assay. Affinity and intrinsic activity of neurohypophyseal peptides

A sensitive and precise method for assaying the water permeability response evoked by neurohypophyseal hormones and their synthetic analogues on the isolated urinary bladder of the toad (Bufo marinus L.) is described. The method permits detection of 8-arginine-vasotocin at concentrations as low as 10(-12)M. This sensitivity, not achieved heretofore with this tissue, results largely from minimizing interference of inhibitory substances by means of an "in vitro circulation assembly." The precision of the method derives from a direct comparison between the cumulative dose-response curve of an agonist of unknown potency acting on one hemibladder and that of a reference compound acting on the contralateral hemibladder. Crystalline deamino-oxytocin is used as the reference standard in this assay. The intrinsic activity of 2-(O-methyltyrosine)-oxytocin, as defined by the maximal response, is 12% lower than that of deamino-oxytocin. All other hormonal peptides investigated have the same intrinsic activity as deamino-oxytocin, even 5-valine-oxytocin, in spite of its extremely low affinity. A comparison of the potencies of 8-arginine-vasotocin vs. 8-arginine-vasopressin, 8-ornithine-vasotocin vs. 8-ornithine-vasopressin, 8-alanine-oxytocin vs. 8-alanine-oxypressin, and deamino-8-alanine-oxytocin vs. deamino-8-alanine-oxypressin suggests that an isoleucine residue in position 3 imparts a higher specificity for binding of the hormonal peptide molecule to the bladder receptor than a phenylalanine residue in this locus.