Lack of effect of alpha-human atrial natriuretic polypeptide on volume reabsorption and p-aminohippuric acid secretion in the rabbit proximal straight tubule.
To assess a possible direct tubular action of alpha-human atrial natriuretic peptide (alpha-hANP), we studied the effects of alpha-hANP on volume reabsorption (JV), transepithelial voltage (VT), and p-aminohippuric acid (PAH) secretion in the rabbit proximal straight tubules (PST) by in vitro microperfusion technique. In superficial PST (SFPST), addition of alpha-hANP at various concentrations (10(-7), 10(-9), 10(-11) M) to the bath solution did not alter JV significantly. Bath alpha-hANP (10(-7) M) did not change VT in SFPST, either. In juxtamedullary PST (JMPST), addition of alpha-hANP (10(-7) M) to the bath solution changed neither VT nor JV significantly. The alpha-hANP (10(-7) M) in the luminal fluid caused no changes in either VT or JV in SFPST. Furthermore, alpha-hANP (10(-7) M) in the bath did not change the rate of PAH secretion in SFPST. Thus, we could not obtain any evidence for direct tubular action of alpha-hANP in rabbit PST. Accordingly, alpha-hANP may increase solute excretion without directly affecting solutes transport in PST of the rabbit kidney.
D000618:Aminohippuric Acids / Q000378:metabolism*; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000378:metabolism; D008433:Mathematics; D010477:Perfusion; D011817:Rabbits; D010130:p-Aminohippuric Acid / Q000378:metabolism*
D000618:Aminohippuric Acids; D009320:Atrial Natriuretic Factor; D010130:p-Aminohippuric Acid