Cyclic nucleotide phosphodiesterases and thyroid hormones.

Cyclic Nucleotide Phosphodiesterases and Thyroid Hormones*

Evidence is presented that modulation of the maximum velocity of a particulate low K,,, cyclic adenosine 3’:5’-monophosphate (cyclic AMP) phosphodiesterase by thyroid hormones is one mechanism for the regulation of the responsiveness of rat epididymal adipocytes to lipolytic agents such as epinephrine and glucagon. Fat cells of propylthiouracil-induced hypothyroid rats are unresponsive to lipol...

Lipids and thyroid hormones.

C O N T E N T S ABBREVIATIONS I. Tin,on3 HORMONE MECHANISMS A. Calorigenic and anabolic effects B. Thyroid hormone entry into cells II. LIPID METAeOLISM A. Cell lipid composition B. Fatty acid synthesis 1. Protein phosphorylation-dephosphorylation 2. Gene expression C. NADPH generation and oxidation 1. Cytoplasm: NADP+--*NADPH 2. Mitochondria: NADP + + NADH,NADPH + NAD + 3. Microsomes: NADPH-*N...

Effects of thyroid hormone deficiency on cyclic adenosine 3':5'-monophosphate and control of lipolysis in fat cells.

Isolated fat cells from hypothyroid rats, in contrast with those from normal animals, lack ability to give a lipolytic response to epinephrine or glucagon. However, activation of triglyceride lipolysis was induced with (N6,02’-dibutyryl cyclic adenosine 3’ :5’-monophosphate), or a combination of epinephrine and phosphodiesterase inhibitors. Adenylyl cyclase was activated by catecholamines or gl...

Cyclic AMP-specific PDE4 phosphodiesterases as critical components of cyclic AMP signaling.

Cyclic Nucleotide Phosphodiesterases from Rat Anterior Pituitary

Phosphodiesterase activities for adenosine and guanosine 3’ : 5’-monophosphates (cyclic AMP and cyclic GMP) were demonstrated in particulate and soluble fractions of rat anterior pituitary gland. Both fractions contained higher activity for cyclic GMP hydrolysis than that for cyclic AMP hydrolysis when these activities were assayed at subsaturating substrate concentrations. Addition of protein ...