Renal sympathetic activation triggered by the rostral ventrolateral medulla is dependent of spinal cord AT1 receptors in Goldblatt hypertensive rats

Spinal cord neurons contribute to elevated sympathetic vasomotor activity in renovascular hypertension (2K1C), particularly, increased actions of angiotensin II. However, the origin of these spinal angiotensinergic inputs remains unclear. The present study aimed to investigate the role of spinal angiotensin II type 1 receptor (AT1) receptors in the sympathoexcitatory responses evoked by the activation of the rostral ventrolateral medulla (RVLM) in control and 2K1C Goldblatt rats. Hypertension was induced by clipping of the left renal artery. After 6 weeks, a catheter (PE-10) filled with losartan was inserted into the subarachnoid space and advanced to the T10-11 vertebral level in urethane-anesthetized rats. The effects of glutamate microinjection into the RVLM on blood pressure (BP), heart rate (HR), and renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively) were evaluated in the presence or absence of spinal AT1 blockade. Tachycardic, pressor, and renal sympathoexcitatory effects caused by RVLM activation were significantly blunted by losartan in 2K1C rats, but not in control rats. However, no differences were found in the gene expression of angiotensin-converting enzyme, angiotensinogen, and renin in the spinal cord segments between the groups. In conclusion, acute sympathoexcitation induced by RVLM activation is dependent on the spinal AT1 receptor in Goldblatt, but not in control, rats. The involvement of other central cardiovascular nuclei in spinal angiotensinergic actions, as well as the source of angiotensin II, remains to be determined in the Goldblatt model.

Interaction between angiotensin II and GABA in the spinal cord regulates sympathetic vasomotor activity in Goldblatt hypertension

Previous studies have been described changes in brain regions contributing to the sympathetic vasomotor overactivity in Goldblatt hypertension (2K1C). Furthermore, changes in the spinal cord are also involved in the cardiovascular and autonomic dysfunction in renovascular hypertension, as intrathecal (i.t.) administration of Losartan (Los) causes a robust hypotensive/sympathoinhibitory response in 2K1C but not in control rats. The present study evaluated the role of spinal γ-aminobutyric acid (GABA)-ergic inputs in the control of sympathetic vasomotor activity in the 2K1C rats. Hypertension was induced by clipping the renal artery. After six weeks, a catheter (PE-10) was inserted into the subarachnoid space and advanced to the T10-11 vertebral level in urethane-anaesthetized rats. The effects of i.t. injection of bicuculline (Bic) on blood pressure (BP), renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively) were evaluated over 40 consecutive minutes in the presence or absence of spinal AT1 antagonism. I.t. Bic triggered a more intense pressor and sympathoexcitatory response in 2K1C rats, however, these responses were attenuated by previous i.t. Los. No differences in the gene expression of GAD 65 and GABA-A receptors subunits in the spinal cord segments were found. Thus, the sympathoexcitation induced by spinal GABA-A blockade is dependent of local AT1 receptor in 2K1C but not in control rats. Excitatory angiotensinergic inputs to sympathetic preganglionic neurons are tonic controlled by spinal GABAergic actions in Goldblatt hypertension.

Genetic variability and resistance of cultivars of cowpea [Vigna unguiculata (L.) Walp] to cowpea weevil (Callosobruchus maculatus Fabr.)

The cowpea weevil (Callosobruchus maculatus Fabr.) is the most destructive pest of the cowpea bean; it reduces seed quality. To control this pest, resistance testing combined with genetic analysis using molecular markers has been widely applied in research. Among the markers that show reliable results, the inter-simple sequence repeats (ISSRs) (microsatellites) are noteworthy. This study was performed to evaluate the resistance of 27 cultivars of cowpea bean to cowpea weevil. We tested the resistance related to the genetic variability of these cultivars using ISSR markers. To analyze the resistance of cultivars to weevil, a completely randomized test design with 4 replicates and 27 treatments was adopted. Five pairs of the insect were placed in 30 grains per replicate. Analysis of variance showed that the number of eggs and emerged insects were significantly different in the treatments, and the means were compared by statistical tests. The analysis of the large genetic variability in all cultivars resulted in the formation of different groups. The test of resistance showed that the cultivar Inhuma was the most sensitive to both number of eggs and number of emerged adults, while the TE96-290-12-G and MNC99-537-F4 (BRS Tumucumaque) cultivars were the least sensitive to the number of eggs and the number of emerged insects, respectively.

PP156. High prevalence of pre-pregnancy overweight and obesity associated with maternal and perinatal complications

INTRODUCTION

High prevalence of pre-pregnancy weight excess, as well as evidence of increased risk of maternal and perinatal complications associated with nutritional states have been observed lately. Considering the possible ethnic and environmental influences few studies have assessed this risk in pregnant Brazilian women.

OBJECTIVES

This study aimed at determining the prevalence of pre-pregnancy weight excess (overweight and obesity) and its association with maternal and perinatal complications in a Brazilian women population.

METHODS

We conducted a prospective cross-sectional study with 3,300 women who had birth care at the Asa Sul Regional Hospital of Brasília - Federal District (FD), from October 2009 to May 2010. Nutritional status was determined by body mass index (BMI), according to WHO criteria (2000): Low weight (BMI<18.5kg/m(2)), Normal weight (BMI between 18.5 and 24.9kg/m(2)), Weight excess (BMI⩾25kg/m(2)), Overweight (BMI between 25 and 29.9kg/m(2)) and obesity (BMI⩾30kg/m(2)). The outcome variables were: pre-clinical complications such as chronic hypertension and diabetes, manifestation of gestational hypertension/preeclampsia, pregnancy duration and resolution as well as perinatal outcomes. The association among these variables was assessed using chi-square (Pearson) and Fisher's exact test. Results were considered significant when p<0.05.

RESULTS

In this population, weight excess before pregnancy had a prevalence of 27.2%, being 19.7% and 7.5% of pregnant women presenting, respectively, overweight and obesity. The prevalence of normal weight was 64.6% and low weight was 8.3%. Comparing the weight excess (BMI⩾25kg/m(2)) group with the normal weight group it was observed predominant hypertension (23% vs. 10%) and diabetes (10.1% vs. 3.6%), prolonged pregnancy (14.4% vs. 10.7%) and cesarean section rate (58.1% vs. 47.2%) in the weight excess group. Newborn weight equal to or greater than 4,000 g (9.5% vs. 4.5%) as well as fetal macrosomia (14.6% vs. 7.4%) also predominated in weight excess group. The comparison among the groups normal weight, overweight and obesity showed predominance of hypertension, diabetes cesarean section rate, newborns weight and fetal macrosomia in the obesity group.

CONCLUSION

In the population analyzed, the prevalence of pre-pregnancy weight excess, particularly obesity, was high and associated with maternal and perinatal complications. Weight excess pre-pregnancy should be considered a risk to the pregnancy, demanding different obstetric care. Efforts should be made so that, in the pre-pregnancy period, women's weight can be as close to the normal weight as possible.

Quantity and quality of oocytes recovered from donor bitches of different ages

In vitro studies that use isolated oocytes benefit from the ability to harvest oocytes of excellent morphological quality in sufficient numbers to allow the replicability of techniques and experiments. The objective of the present study was to verify the effect of the age of the donor bitch on the quantity and quality of oocytes recovered from isolated ovaries, using the slicing technique. Ten bitches (45 days to 13 years) were ovariohysterectomized, and the ovaries were placed in phosphate buffered saline (PBS), supplemented with bovine fetal serum (5%), and oocyte-cumulus-complexes (OCCs) were obtained by slicing the ovarian tissue. The OCSs were classified morphologically as Degree I (DI, best), Degree II (DII) and degenerated. A total of 427 oocytes were acquired, including 81, 109 and 237 that were graded as DI, DII and degenerated, respectively. Slicing yielded no OCS from animals < 2 months of age. In senile (> 9 years) bitches, bitches, there were more oocytes per bitch, compared to adult (2-6.5 years) bitches, but fewer DI oocytes, and more DII and degenerate oocytes. We inferred that using donors that were post-pubertal but not senile, would assure the recovery of high-quality oocytes by the slicing method. Additional studies are required to assess the quality of oocytes collected from pre-pubertal versus post-pubertal bitches < 2 years of age.

Neuropeptide Y in the medial basal hypothalamus and medial preoptic area during the induction of LH surge may be controlled by locus coeruleus

The multiple control of gonadotropin releasing hormone (GnRH)/luteinizing hormone (LH) secretion involves locus coeruleus (LC) and neuropeptide Y (NPY). The objective of the present study was to analyze the possible contribution of the LC to the control of NPY activity in the medial basal hypothalamus (MBH) and medial preoptic area (MPOA) during the LH surge induced by estrogen (E(2)) and progesterone (P(4)). Ovariectomized adult Wistar rats were submitted to the hormone replacement and to the LC bilateral lesion (lesioned groups) or sham surgery (control groups). On the day of the experiment the rats were decapitated at 11:00, 13:00, 15:00 and 17:00 h for plasma and brain collection. Plasma LH was determined by radioimmunoassay. MBH and MPOA were microdissected for the measurement of NPY by enzyme immunoassay. NPY mRNA levels in MBH were assessed by the ribonuclease protection assay. The results showed that LC lesion: decreased the plasma LH; increased the content of NPY in the MBH and reduced the increase of NPY content in the MPOA during afternoon in which LH surge was induced. The increased NPY content in MBH was not associated with an increase of the respective mRNA content, suggesting the action of postranscriptional and/or postranslational mechanisms. In conclusion, the NPY activity in the MPOA on LH surge induced by estrogen and progesterone could be controlled by LC through two ways, at least: one direct way, by the release of NPY from LC neurons terminals that innervate the MPOA and they release NA and NPY; one indirect way, by the control of release but not synthesis of NPY from neurons in the MBH which innervate the MPOA.

[Fishing yield and chemical pollutants in the water of Billings Reservoir, São Paulo (Brazil)]

Através da análise dos surfactantes determinados pelo método colorimétrico com azul de metileno, e dos metais pesados determinados por espectrofotometria de absorção atômica, como o cádmio, chumbo, cobre, cromo, mercúrio e zinco, foi caracterizada a poluição na Represa Billings, SP (Brasil), enfatizando a qualidade sanitária da água e a contaminação dos peixes. Com base nos dados coligidos, é mostrado o perigo potencial que representa o consumo do pescado proveniente da Billings, se bem que a pesca comercial esteja hoje praticamente restrita às cabeceiras dos braços dos rios Capivari e Pequeno, na junção próxima a Ribeirão Pires e nos braços dos rios Curucutu e Taquacetuba. Os dados da CEAGESP - Companhia de Entreposto de Armazéns Gerais do Estado de São Paulo - indicam que, no ano de 1980, apenas 64 toneladas de peixe provieram de São Bernardo do Campo.