Enhanced vascular effects of the Ca(2+) channel agonist Bay K 8644 in pregnant rabbits.

Hemodynamic studies were performed to determine if blunting of vascular pressor responsiveness to vasoconstrictors during pregnancy may be due to impaired L-type voltage-dependent calcium channels (L-VDCC). Bay K 8644 (BAY), an L-VDCC agonist, was infused in pregnant and nonpregnant anesthetized rabbits (10, 20, 40, and 60 microg/kg) and pregnant and nonpregnant conscious, chronically instrumented (conscious) rabbits (10, 25, and 50 microg/kg). BAY infusions resulted in greater elevation of mean arterial pressure in both anesthetized pregnant (n = 6) vs.

Interaction of gender and dietary protein on renal growth and the renal growth hormone-insulin-like growth factor axis.

The female kidney tends to be smaller, have a lower glomerular filtration rate, and be less susceptible to glomerulosclerosis than the male kidney. Insulin-like growth factor-I (IGF-I) is a peptide growth factor that appears to be important for normal and adaptive kidney growth. The purpose of this study was to compare the kidney growth response of the male and female rat kidneys to increased dietary protein intake and to see whether differences in IGF-I production or receptor expression might underlie any gender differences seen.

Impact of surgery on nitric oxide in rats: evidence for activation of inducible nitric oxide synthase.

We investigated the effect of euvolemic surgical preparation, on chemical indices of activity of the nitric oxide (NO) system, in anesthetized, acutely prepared rats. The urinary excretion of NO2+NO3 (UNOXV) and cGMP (UcGMPV) increased progressively during the experiment. Pretreatment with aminoguanidine or dexamethasone, inhibitors of inducible NO synthase (iNOS), prevented the increase in UNOXV and UcGMPV but had no impact on mean arterial pressure (BP), renal vascular resistance (RVR) or GFR.

Pregnancy enhances the pressor response to thromboxane analogues in rabbits.

In this study, we first tested the hypothesis that the previously demonstrated circulatory failure and thrombocytopenia induced by intracaval administration of thromboxane A2 (TxA2) analogues in nonpregnant (NP) rabbits [G. Losonczy, I. Mucha, J.

Retinoic acid inhibition of thyroxine binding to human transthyretin.

All-trans retinoic acid is a potent inhibitor of [125I]-thyroxine (T4) binding to human erythrocyte membranes and can block the activation by thyroid hormone of erythrocyte Ca(2+)-ATPase [J. Biol. Chem.