Antidiuretic responses to osmotic cutaneous stimulation in the toad, Bufo arenarum. A possible adaptive control mechanism for urine production.
Osmotic stimulation of the skin of the toad Bufo arenarum with isotonic (115 mM) or hypertonic (400 mM) NaCl solutions produced a marked and reversible antidiuresis within 5 min. No changes in plasma osmolarity were detected in the course of this response. Hypophysectomized animals exhibited a lower and delayed antidiuresis when exposed to a hypertonic environment (400 mM NaCl). This antidiuretic response was drastically reduced in normal toads after ten consecutive days of administration of the sympatoplexic guanethidine. The existence of a feed-forward control of urine production initiated by cutaneous osmotic sensors and involving an adrenergic component is proposed.
Petriella
S
S
Laboratorio de Fisiologia del Comportamiento, Instituto de Biologia y Medicina Experimental, Buenos Aires, Argentina.
Reboreda
J C
JC
Otero
M
M
Segura
E T
ET
D000818:Animals; D002022:Bufo arenarum; D004231:Diuresis; D007016:Hypophysectomy; D008297:Male; D009995:Osmosis; D012867:Skin / Q000378:metabolism; D012879:Skin Physiological Phenomena; D012965:Sodium Chloride / Q000493:pharmacokinetics; D014556:Urine / Q000502:physiology
D012965:Sodium Chloride