Biomaterial Database

Modulation of renal adrenergic effector mechanisms by calcium entry blockers. 1987

J C Pelayo

Micropuncture studies in anesthetized Munich-Wistar rats were undertaken to investigate the effects of calcium channel blockade on the glomerular hemodynamic responses to 3-Hz renal nerve stimulation. Stimulation alone increased afferent and efferent arteriolar resistances by 85 and 35%, respectively. Because of these increases both single nephron plasma flow and glomerular capillary hydrostatic pressure difference fell to levels significantly below control, leading to a 26% reduction in single nephron filtration rate (P less than 0.005). These changes, however, were largely attenuated during calcium channel blockade (verapamil, nifedipine). Single nephron filtration rate was only decreased by 14% (P less than 0.05) due to a reduction in single nephron plasma flow. The role of angiotensin II on the residual vasoconstrictive effect of stimulation was also investigated. Pretreatment with an angiotensin-converting enzyme inhibitor (MK 421) of rats infused with verapamil abolished the residual vasoconstriction. The data suggest that calcium influx is an important step for the vasoconstrictive effects of the renal nerves. Additionally, angiotensin II contributes to increased vascular resistance during renal nerve stimulation via a separate, calcium channel mechanism.

UI	MeSH Term	Description	Entries
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D007678	Kidney Glomerulus	A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.	Glomerulus, Kidney
D008297	Male		Males
D009543	Nifedipine	A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.	Adalat,BAY-a-1040,Bay-1040,Cordipin,Cordipine,Corinfar,Fenigidin,Korinfar,Nifangin,Nifedipine Monohydrochloride,Nifedipine-GTIS,Procardia,Procardia XL,Vascard,BAY a 1040,BAYa1040,Bay 1040,Bay1040,Monohydrochloride, Nifedipine,Nifedipine GTIS
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D005919	Glomerular Filtration Rate	The volume of water filtered out of plasma through glomerular capillary walls into Bowman's capsules per unit of time. It is considered to be equivalent to INULIN clearance.	Filtration Rate, Glomerular,Filtration Rates, Glomerular,Glomerular Filtration Rates,Rate, Glomerular Filtration,Rates, Glomerular Filtration
D000320	Adrenergic Fibers	Nerve fibers liberating catecholamines at a synapse after an impulse.	Sympathetic Fibers,Adrenergic Fiber,Fiber, Adrenergic,Fiber, Sympathetic,Fibers, Adrenergic,Fibers, Sympathetic,Sympathetic Fiber
D000804	Angiotensin II	An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.	Angiotensin II, Ile(5)-,Angiotensin II, Val(5)-,5-L-Isoleucine Angiotensin II,ANG-(1-8)Octapeptide,Angiotensin II, Isoleucine(5)-,Angiotensin II, Valine(5)-,Angiotensin-(1-8) Octapeptide,Isoleucine(5)-Angiotensin,Isoleucyl(5)-Angiotensin II,Valyl(5)-Angiotensin II,5 L Isoleucine Angiotensin II,Angiotensin II, 5-L-Isoleucine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia