5-Hydroxytryptamine: a second diuretic hormone in Rhodnius prolixus.
Bioassays of 5-hydroxytryptamine (5-HT) in fifth-instar Rhodnius prolixus haemolymph using Calliphora salivary glands indicate that: (1) biologically active 5-HT is present, (2) in unfed animals there is not enough 5-HT to stimulate Malpighian tubule fluid secretion, and (3) there is enough 5-HT soon after the initiation of feeding to stimulate rapid tubule secretion. The 5-HT receptor antagonists ketanserin and spiperone reversibly and selectively inhibit 5-HT-induced fluid secretion, indicating the presence of specific 5-HT receptors on Rhodnius Malpighian tubules. The data provide evidence that 5-HT is a naturally occurring hormone acting with a previously described peptide hormone to regulate diuresis in this species.
Maddrell
S H
SH
Department of Zoology, Cambridge, England.
Herman
W S
WS
Mooney
R L
RL
Overton
J A
JA
D000818:Animals; D001681:Biological Assay; D004231:Diuresis / Q000502:physiology*; D005260:Female; D006458:Hemolymph / Q000737:chemistry; D007447:Invertebrate Hormones / Q000378:metabolism; D007814:Larva / Q000032:analysis; D008317:Malpighian Tubules / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D011985:Receptors, Serotonin / Q000032:analysis / Q000378:metabolism; D012239:Rhodnius / Q000032:analysis / Q000502:physiology*; D012469:Salivary Glands / Q000187:drug effects / Q000378:metabolism; D012701:Serotonin / Q000032:analysis / Q000502:physiology*; D012702:Serotonin Antagonists
D007447:Invertebrate Hormones; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D012701:Serotonin