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Ovarian muscularis of the stable fly Stomoxys calcitrans : Its structural, motile, and pharmacological properties
Author(s) -
Cook Benjamin J.,
Peterson Tara
Publication year - 1989
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.940120103
Subject(s) - biology , stable fly , ovary , stomoxys , anatomy , medicine , endocrinology , corpus allatum , insect , muscidae , zoology , ecology , juvenile hormone
The muscles of the ovary of the stable fly ( Stomoxys calcitrans ) appear to consist of two groups: (1) a network of stellate muscle cells that cover the surface of the ovary and (2) fibers that surround the ovarioles. Innervation of the ovaries was largely restricted to the region of the pedicels. The structural arrangements of the ovarian muscles provided the basis for two distinct patterns of movement. The contraction of the sheath that surrounds the ovary produced the appearance of a pulsing sphere, while the activation of muscle fibers that encompass the ovarioles may cause a vertical translation of eggs within the tubes. The various patterns of motility derived from the combined and separate actions of these two groups of muscles are described. Oscillations in the size of the ovary were the most prominent and frequent kind of spontaneous activity observed. A complete cycle of oscillation ranged from 200 ms to 4 s. Day‐old stable flies consistently had the highest rate (30%) of ovarian sheath compression of the three age groups examined, while 2‐day‐old flies had the lowest (less than 10%). Seven‐day flies had inconsistent rates that ranged from o to 25%. Two kinds of ovarian compression were recognized on impedance myographs on the basis of small and large amplitudes. Changes in tonus were also detected. Octopamine produced large increases in the amplitude of spherical compressions at 10 −7 M. The neuropeptide proctolin (10 −9 M) caused changes in both the frequency and amplitude of ovarian contractions. Glutamic acid consistently caused a marked reduction in the amplitude of ovarian compressions.