Abbott, Cyril E.

English

UARK (University of Arkansas )

Ovarian Pulsation and Allied Phenomena in Lucilia Sericata Meig.

ScholarWorks@UARK

Journal of the Arkansas Academy of ScienceVolume 2 Article 131947Ovarian Pulsation and Allied Phenomena in LuciliaSericata Meig.Cyril E. AbbottHarding CollegeFollow this and additional works at: http://scholarworks.uark.edu/jaasPart of the Entomology CommonsThis article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able toread, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking priorpermission from the publisher or the author.This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academyof Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu, ccmiddle@uark.edu.Recommended CitationAbbott, Cyril E. (1947) "Ovarian Pulsation and Allied Phenomena in Lucilia Sericata Meig.," Journal of the Arkansas Academy ofScience: Vol. 2 , Article 13.Available at: http://scholarworks.uark.edu/jaas/vol2/iss1/1339IOVARIAN PULSATION AND ALLIED PHENOMENA IN LUC ILIA SERICATA MEIG.Cyril E. Abbott, Harding College, SearoyOn opening the abdominal cavity of a living, female fly withundeveloped ova, one generally finds the ovaries contractingrhythmically. Contraction chiefly Involves the calyces, for con-traction of the ovarloles Is spasmodic and ephemeral, and theoviducts contract only occasionally, usually as the result ofmechanical stimulation.This pulsation, though affected by stimuli external to theorgans, Is more or less independent of them, for the ovaries oftencontinue this action for hours In Ringer's solution, even whenseparated from the body of the Insect. Moreover If, for anyreason, ovaries which have been left for some hours have ceasedto pulsate, the addition of warm (30°C.) Ringer's will often Ini-tiate pulsation for several hours longer.The ovaries are seldom motionless in a freshly dissectedspecimen, but sometimes pulsate feebly and soon stop, apparentlyas a result of the shock of operation. In such cases any one of avariety of stimuli may Initiate pulsation. Crystals of ordinarytable salt dropped upon them will often have this effect; so too,will sugar, although ItIs less effective. Mechanical stimuli In-itiate pulsation; even a stream of liquid passed over the organsoften having that effect. But, with the specimens Iused, nosingle stimulus Invariably produced the same result - exceptingeserlne and acetylchollne bromide, the effects of which will bedescribed later in this paper. Occasionally none of the stimuli,singly or together, had any observable result upon pulsation.There is no evident consistency In the rate, vigor, or syn-chrony of ovarian pulsation. Even In a single specimen the twoovaries seldom contracted at the same rate, although it was notunusual for them to do so alternately. Contraction often appearedto take place simultaneously In the entire ovary; at other times avisible wave of contraction passed from the margins Inward towardthe center, which became briefly elevated, so that the surface ofthe organ was momentarily convex. Less frequently a wave of con-traction passed from the cephalic margin of the organ toward theoviduct. Cases of Incomplete contraction were also observed: Insuch cases the margins of the organ were active, while the rest ofthe body was motionless.The period of contraction varied from 0.8 seconds to nearly aminute, depending upon the specimen and circumstances. In somecases the rate Increased or decreased without apparent cause. Somespecimens exhibited an increase Inboth rate and vigor for a timeand then gradually slowed and finally stopped.Contraction of Individual ovarioles was observed only a fewtimes and then only In fresh specimens. Each acts Independentlyof the others. A wave of constriction passes from the free end ofthe organ to the calyx. The oviducts contract occasionally, gen-erally by shortening of the tube. Erratic contractions of the ac-cessory glands and spermathecal ducts also occur. Contractions ofthe latter may bring the reservoirs in contact with one another Ina way which suggests a boxer striking his fists together.Pulsations of the ovarian calyces appear never to occur inflies with matured ova; nor is any movement of the reproductiveducts evident In such specimens. Movements which produce descentof the ova must occur, but perhaps are Inhibited in dissected39Journal of the Arkansas Academy of Science, Vol. 2 [1947], Art. 13Published by Arkansas Academy of Science, 194740specimens. The close packing of the ova and consequent limitationof free space In such specimens must, however, limit Internalmovements: ItIs difficult to understand how pulsation could takeplace under such circumstances.In considering the effects of eserlne and acetylchollne uponovarian pulsation It Is necessary to point out that the experi-mental results obtained upon other organisms with the aforemen-tioned substances have not been entirely consistent. A number ofstudents have pointed out that acetylchollne, although Itraisesthe blood pressure, also produces vasodllatlon. Hellbrunn hassummarized the results of the studies on the action of the drug,and the few references Ihave studied In detail support his con-clusions that the action of acetylchollne varies with differentorganisms and under different circumstances. Interpretations alsodiffer as to the effect that acetylchollne .has upon various Inver-tebrates. Thus, while Beauvallet maintains that Its action on thegut of molluscs Is similar to the results obtained with the gut ofvertebrates, Roeder (1939), In experimenting on the central ner-vous system of Insects, concludes that Injected acetylchollne, evenIn the presence of eserlne has little effect upon the behavior ofthe experimental animal. He emphasizes the fact that the effectof eserlne alone may result from a chollnerglc condition broughtabout by Inhibition of the esterase action of the tissues on ace-tylchollne normally produced. He did find that acetylchollne pro-duces Increased impulse discharges In Isolated Insect nerve.Thus It Is difficult to decide whether the effects of eserineresult from the action of the drug directly or to suppression ofthe organic esters which act upon acetylchollne. Be that as itmay, when eserlne is added to the Ringer's solution In which liv-ing fly ovaries are kept there is usually an increase in the vigorand rhythm of contraction. A higher concentration of the drug In-hibits all movement; the ovaries remaining strongly contracted.(Similar effects, by the way, may be observed on the activities ofthe gut). On the other hand, acetylchollne alone seems to reduceboth the speed and ryhthm of contraction, and in excessive amountsproduces a condition of permanent relaxation and stasis. Pulsa-tion Is most nearly normal, though Increased, when eserlne andacetylchollne are applied together. The results of these observa-tions appear in the accompanying table.40Journal of the Arkansas Academy of Science, Vol. 2 [1947], Art. 13http://scholarworks.uark.edu/jaas/vol2/iss1/1341Table I. Effects of Eserine and Acety IcholineHydrobromide on Ovarian Pulsation in LuciliaSpecimen Acetylcholine Specimen Eserine1 Rate of pulsation in- 1 Intermittent, irregularcreased; arrhythmic, with pulsations becomingpartial relaxation. rhythmic and strong.2 Pulsation initiated in mo- 2 Pulsations'irregular buttionless organs; period of intensified,relaxation longer thanthat of contraction.3 Pulsation in one ovary 3 Contractions of right ovaryonly. Partial relaxation complete; left relaxed andof active organ. motionless.4 Organs relaxed and motion- 4 With acetylcholine, slightless excepting at margins. acceleration and completecontraction.5 Pulsations slow and incom- 5 Pulsations resumed whichplete, but slowly acceler- had stopped under acetyl-ating. choline.6 Right ovary arrhythmic and 6 Pulsation feeble. Finallypartially relaxed; leftrhythmic and vigorous.stopped with ovaries con-tracted.7 Ovaries motionless in re-laxed position.7 With acetylcholine, pulsa-tions initiated fromstasis .8 Pulsation3 slower aftereserine .8 Results negative.9 Slower after eserine; inter- 9 Pulsations slower but morevening periods of inactivity complete.in relaxed condition.10 Pulsations slower after eser- 10 Ovaries stopped in contractine with partial relaxation. ed position. Solution voryconcentrated.The function, If any, of ovarian pulsation, Is not clear.Each ovary Is richly supplied with tracheal branches from two ad-jacent spiracles. This suggests that the organ requires a rela-tively large amount of oxygen, and Itmay be that pulsation In-creases its diffusion. On the other hand, it may tfe that pulsa-tion has no significance beyond the fact that automatic contrac-tility is an Inherent property of the calyx tissue.ReferencesBeauvallet, M. Comp. Rend. 3oc. Blol. France, 127(3), 213-214.Roeder, K. D. Blol. Bui., 76, 183-189. 1939.Roeder, K. D. and Sonja. Jour. Cell, and Compar. Physlol., 14,1-8. 1939.Hellbrunn, L. V. Outline of General Physiology. W. B. Saunders,Philadelphia. 1937.41Journal of the Arkansas Academy of Science, Vol. 2 [1947], Art. 13Published by Arkansas Academy of Science, 194742Journal of the Arkansas Academy of Science, Vol. 2 [1947], Art. 13http://scholarworks.uark.edu/jaas/vol2/iss1/13

https://scholarworks.uark.edu/cgi/viewcontent.cgi?article=1073&amp;context=jaas

Ovarian Pulsation and Allied Phenomena in Lucilia Sericata Meig.

Abstract

Similar works

Full text

Available Versions

UARK (University of Arkansas )

ScholarWorks@UARK