Sex-specific regulation of neuronal functions in Caenorhabditis elegans: the sex-determining protein TRA-1 represses goa-1/Gα.

Females and males differ substantially in various neuronal functions in divergent, sexually dimorphic animal species, including humans. Despite its developmental, physiological and medical significance, understanding the molecular mechanisms by which sex-specific differences in the anatomy and operation of the nervous system are established remains a fundamental problem in biology. Here, we show that in Caenorhabditis elegans (nematodes), the global sex-determining factor TRA-1 regulates food leaving (mate searching), male mating and adaptation to odorants in a sex-specific manner by repressing the expression of goa-1 gene, which encodes the Gα subunit of heterotrimeric G (guanine-nucleotide binding) proteins triggering physiological responses elicited by diverse neurotransmitters and sensory stimuli.

Furosemide-induced alterations in the electrolyte status, the function of renin-angiotensin-aldosterone system, and the urinary excretion of prostaglandins in newborn infants.

To assess the responsiveness of the renin-angiotensin-aldosterone system of the neonate to acute furosemide stimulation and the role of renal prostaglandins in mediating the response of the renin-angiotensin-aldosterone system, this study was carried out to determine simultaneously plasma renin activity, plasma aldosterone concentration, urinary aldosterone, prostaglandin E, and prostaglandin F2 alpha excretion along with determination of plasma electrolyte concentration and urinary electrolyte excretion. Measurements were made on 19 newborn infants with mean birth weight and gestational age of 3009 g (range, 2700 to 4150 g) and 38.7 wk (range, 36 to 41 wk) at the age of 4 to 7 days before and after IM administration of furosemide in a dose of 1 mg/kg.

On the mechanisms of renal sodium handling in newborn infants.

In an attempt to delineate the specific tubular defect in sodium reabsorption in low-birth-weight neonates, fractional sodium excretion (CNa/CCr), distal tubular sodium delivery (CNa+CH2O), and tubular sodium reabsorption [(CH2O/CH2O+CNa) X 100] were determined in 8 healthy premature and 10 full-term newborn infants. The mean birth weight was 1,701 g (range: 1,240--2,120 g) and the mean gestational age was 32.6 weeks (range: 28--35 weeks) for premature; and 3,199 g (range: 2,670--3,670 g) and 38.

Function of the renin-angiotensin-aldosterone system in relation to electrolyte balance in the small-for-date neonate.

To assess the influences of intrauterine growth retardation on the electrolyte status and the activity of renin-angiotensin-aldosterone system of newborn infants, sodium and potassium balance, as well as plasma renin activity, plasma aldosterone concentration and urinary aldosterone excretion were determined simultaneously in a group of healthy growth retarded and healthy normally grown neonates. It was observed that intake, urinary excretion and retention rate of sodium and potassium as well as the plasma sodium and potassium levels were essentially the same in the two groups. Similarly, no significant difference was found in plasma renin activity, plasma aldosterone level and urinary aldosterone excretion between the neonates whose birth weight was small or appropriate for gestational age.