Preservation of renal compensatory growth in uninephrectomized rats by low-dose cyclosporine.

The growth-inhibitory effect of prednisone is a serious drawback to its use in kidney graft recipients. At high doses, cyclosporine also inhibits somatic growth in animals. Furthermore, cyclosporine, in addition to being nephrotoxic in patients, is reported to inhibit compensatory renal growth in uninephrectomized rats.

Frog brain and liver show evolutionary conservation of tissue-specific differences among insulin receptors.

The insulin receptors of frog brain and liver show features typical of other insulin receptors with regard to affinity and specificity of binding to insulins and proinsulin, solubility in Triton X-100, binding to and elution from wheat germ agglutinin, and insulin-sensitive tyrosine kinase activity. Likewise, the brain and liver receptors differ from one another in electrophoretic mobility and susceptibility to treatment with neuraminidase, analogous to brain and liver receptors of reptiles, birds, and mammals; while the functional implications of these differences are unknown, their evolutionary conservation for 400-500 million years suggests the possibility that they might have importance.

Comparison of verapamil and nifedipine in thrombosis models.

Calcium blockers and calmodulin antagonists have been reported to inhibit the aggregation of blood platelets in vitro. In the present study, the effects of two calcium blockers, verapamil and nifedipine, were compared in several rodent thrombosis models. In rat and mouse platelet-rich plasma, preincubation with either verapamil or nifedipine had a dose-dependent inhibitory effect on collagen-induced aggregation (P less than 0.

Insulin receptors in lizard brain and liver: structural and functional studies of alpha and beta subunits demonstrate evolutionary conservation.

Specific insulin receptors are present in the liver and brain of the lizard Anolis carolinesis. In this study, the specific binding of 125I-insulin to the receptors showed time, temperature and pH dependency. Specific binding to crude membranes prepared from brain was 1-2% of the total radioactivity added compared to 4-5% in the crude membranes prepared from liver.

Plasma cholesterol levels in eviscerated rats.

Eviscerated rat models with a functional liver in which the kidneys or pancreas could be left in situ or removed were used. We found that removal of the gastrointestinal tract leaving the liver and kidneys intact resulted in a significant elevation above normal of the plasma cholesterol. In the absence of the liver, esterified cholesterol is decreased.