Responses of frog skin, Rana pipiens, calcium ion transport to parathyroid hormone, calcitonin, and vitamin D3.
The responses of cutaneous Ca2+ transport to parathyroid hormone, calcitonin, and vitamin D3 were evaluated in intact Rana pipiens and isolated skins from this species. Parathyroid hormone (12 pmol g-1) stimulated Ca2+ influx in intact frogs but not in isolated skin (10-100 pmol ml-1) unless the frogs had been pretreated with vitamin D3 injections (100-300 microgram day-1) for 3 days prior to isolating the skins for flux measurements. Pretreatment of intact frogs with vitamin D3 for 3 days (100 microgram day-1) also resulted in greater responses to PTH (6-12 pmol g-1). Vitamin D3 (most likely after conversion to 1,25(OH)2D3) had a direct stimulatory effect on Ca2+ transport in isolated skins after three daily doses of 500 microgram of D3. Calcitonin also stimulated Ca2+ influx in both intact frogs (24 pmol g-1) and isolated skins (25-100 pmol ml-1). We conclude that parathyroid hormone, facilitated by vitamin D, stimulates Ca2+ influx in the skin of R. pipiens. We also conclude that calcitonin is stimulatory for cutaneous Ca2+ influx in this species.
Biological Sciences Department, California State Polytechnic University, Pomona, California, 91768, USA.
D F
DF
Stiffler
J C
JC
Yee
J D
JD
Tefft
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002116:Calcitonin / Q000008:administration & dosage / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002762:Cholecalciferol / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D066298:In Vitro Techniques; D010281:Parathyroid Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D011894:Rana pipiens; D012867:Skin / Q000187:drug effects / Q000378:metabolism*
D010281:Parathyroid Hormone; D002762:Cholecalciferol; D002116:Calcitonin; D002118:Calcium