Some effects of oxytocin on in vitro preparations of uterine muscle : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Veterinary Science of Massey University

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S01lli EFFECTS OF OXYTOCIN ON IN VITRO PREPARATIONS

OF UTERINE MUSCLE

BY

HUli:PHR.EY GETHIN REES D. V .11. N .D .A.

OF

Department of Animal Health 1\:assey University

A Thesis submitted in Partial Fulfilment of the Requirements for the Degree of

Master of Veterinar,y Science of Massey Universit,y

October, 1 967.

ACKNOWLEDGEMENTS

The candidate wishes to record his indebtedness to Professor E.D. Fielden, of the Clinical Science Department, whose continued guidance and interest made this stuqy possible.

He wishes to acknowledge the advice of Professor D.A. Titchen, of the P~rsiology Department, who provided the laboratory equipment, and the encourageQent of Professor D.S.

Flux, Dairy Husbandry Department, who provided eA~erimental

facilities.

Special thanks are e:>:tended to the late Mr. A. Glenday, D.S.I.R., for assistance with statistica~- problems, and to

Dr. R.A. Munford. of the Dairy Husbanctry Departn:ent, whose helpful advice on biological problems and experimental design is gratefully acl:nov1ledged.

Thanks are due to Mr. B. Barnett for preparing

physiological solutions, to N~s. J. Lang for technical assistance, to Mr. G.H. Burns for photographing figures and to the Library staff for obtaining references. Thanks are also due to Organon Laboratories Limited, for providing the steroid hormones used in the main experiments.

The candidate wishes to acknowledge the advice of his colleagues at the Faculty of Veterinary Science, Massey Universit.y,

and in particular the advice of Dr. W.A.G. Charleston of the Department of Animal Health. Special acknowledgement with thanks is offered to Dr. D.B. Galloway and Mr. D.E. Johnston of the University of Melbourne, for constructive criticism of Chapter I.

This thesis was completed after appointment to the staff of the University of Melbourne. Professor Blood's forbearance with respect to time is gratefully acknowledged.

Finally sincere thanks to ~ wife for her encouragement and support.

Signed

/ _I 1 . _{,.._} ^J

• \. y ·. • • • •

!£~JdL_9! CONTENTS

IITTJ.ODUCri' ION

I. Influences of "'cnc I~ervous Syste1.. on the Uterus

Surrrn['t.I".J' O"!.,... :·!Grvouu ~ffects

II. Eoruon.'l- I:1fLwnccs 8:1 t:w :Jtcrus

' _{I •} Centre .;t!:--:s an:i ?".c8~c~·t8=.;'31-:s

'i) D::.~c~lt.;::Ji:a.J . .:·.cti ^Jl:s of Oes-:r,)_::;ens

(a, ·.·.re.:tcr Content

I · ' I ^l

\O) onic excnunce

(c) ?rotein Syr:t:wsis

(d) l1:·.\:; :;1-J '.:'0!1US

(b) 0:-:ytocin -·~c ticn c: t Par·::uri tion (c) l'terine Res·.)onsc to O::::ytocin (d) Species

(e) Sta{;e o:' Cycle and Stage of Precnancy

(f) Side Effects (g) Ionic Influence Sw:iffiary of Hormonal Effects B. Recordin~ Uterine l1ctivity in~

I . External methods

1 • Recording of Electrical Potential 2. Recording of l::echanical Changes

Pa~e.

1

3 3 4 5 5 5

6

,.

0

7 7

...., I

7 8 8

9 9 9

10 11 12 1 2

13 14 14

(ii)

II. Intra-abdor.1inal methods 1 • ~lcctrical Potential 2.

Jo 7

Pressure Chances Telemetric methods Sur:.:·.:ary o_ in vivo cctlwd.s C. Reco:cdinc Uter:Lno l.ct:.vit_y in vitro

j).

T ?urtial Severance of Utcr~~o Connections II. ':'otaJ. :..;::c::.sion of the Uterus

Conc1us ~on on in vitro r.:OtllcC.s Ph.)rsiccll ~~actors

Pre~)C:..l ... ^,..J.. tic:ns

Influcncin_:; the "·~ctivity of Uterine in v:~tro

1 • ,..,

'-•

3.

':'ensi~~, jco!.otri~ ;u~d isotonic contraction

(i) ~rra~~~ of different ions

?o-:e1.s2iur: io~s

(c) (d)

( '-^{,, '\} )

(::)

Oxytoci!l

Tochniq_uc

(a) l,Ic:::;nific.:~ti.on of the levo:-

(b) ::_,"'requency ru1d r.,acni i-ud.e o:f' stimul.:1tions (c) O:,:ygen supply

(d) Source of enere,Y

Sum1ary of the physical factors affecting in vitro preparations

CHP..PTER 2. ~~~ Yli'l'H GUll-lEA PIGS A. Introduction

B. Techniques used in Experiments on Guinea Pigs

Page

17

17 17 18

19 19 19 20

20 2'i

23 23

24

2^j-,· ^.

2'+ ¹

24

25

26 26 26 27 27

27

29 29 29

1 • ,.., c...

(iii)

Housinc and FeedinG ';.'rea tment

3. :Lx:--::.nino.tion of the Specimen

(i)

(ii) (iii)

.·.ttachment of the Specioen

•. dr::inistration of Ox::,·tocin

lr... .::..ssess1:1er:t of ft..esponsc

5. Sto.tin::ico.l inalysis

1. i:ethod

2. 2csults and Conclusions

D. :::;x:pcri.:wnt

:::r

. ,

....

1 . :.:ethod

,.

~

.

^{2osults and} Discussinn

I • ')

~. J.c.:;ultn

3.

Co:1clu3ion

1 • Housint; and diet 2, 'l'rentment

3. Examination of the specioen (i ) Apparatus

(ii) Ringer solution

(iii ) Attachment of the specimen (iv) Administration of oxytocin

Page

30 30 30 31 31 31

32

33 33

34 34 35

3'7

,;::;

'~·...)

47 47 47 47 48 49 50

~. ·weight measurements

5. Assessment of response 6. Statistical lu'1alysis

C. Experiment I

1 • Lethod H .•

(

.

^\

l) (ii)

J,:ethod :1esul b (iii) Corru::cnt

2. .:ethod B.

(i) I.:ethod

( ii) Result s

(iv)

3. Co~1clusions from J.at 1:;:-::periment I

D. Ex:pcrlner:t II (

.

^\

l j ;:eth::>d

( .. )

,ll =~esul ts (iii)

~-e th::lCl ( ii. ~

' ^~lesul tn

Conclusic:1s fro:.i Preli.r:lino.r~' ~~-=l~erir.:ents

c:~L~?rR:L !, .• ':'.I~.C'~OJ.L·J~· ^~}:_2':_:t n :::.::.;'l'S ·;,T..:.1I ^r:,-~, ~.l..:.J,..:.oo lL·._rr

----

' Introdu:)tion

"' ·

B. General Exp crimen tal J,:ethod

c.

^{Factorlal Experiment I}

(i) J,Iethod (ii) Results (iii) Comment

D. Factorial Experiment I I (i) Method

(ii) Results

(iii) Joint i;nalysis of Factorial Experiments I & I I

Page

50 50 51

51 51 51 52 52

53 53 53 53

55 55 55 56 56 57 58 58

60

60 61 62 62 62 63

6~

6~

65 66

(vl

E. Alternative 1tethods of Measuring Response

I. Highest amplitude following administration II. Area Measurement

(i) Method (ii) Results

(a) Differences between contractions (b) Effects of pretreatment

(c) Interaction effects Summary of Area I.:easurement Findings F. Variant of Factorial Experiment II

(i) Method

(ii) Analysis of results (iii) Comment

Conclusions from Factorial Experiments

CHAPrER 5. FtJ.RTHER. CO:MPAR.ISONS OF _{HORMONES ON}

-

_THE RESPONSES OF

-

THE EFJ:t':ECTS OF TiiE~ERmE STEROID MUSCLE OF THE RAT

A. Introduction B. Experiment I.

(i) Method (ii) Results (iii) Comment C. Experiment

·rr.

(i) Method (ii) Results

Conclusions from experiments in Chapter 5.

Page

66 66 68 68 70

70 70 72

73 73 74 74 76 76

77 77 77 77 78 79 79 79 81 82

(vi)

Page

CHAPTER 6. SlThiliiARY AND CONCLUSIONS ₈₃

REFERENCES ₉₁

APPENDICES

LIST OF TABLES

Table I Facing page 35

Table !a On page 37

Table II Facing page 40

Tables IIa, lib, lie, lid Facing page 41

Table III Facing page 52

Tables Ilia, IIIb, IIIc, IIId Facing page 53

Table IV Facing page 54

Table

v

Facing page 55

Table Va On page 55

Table VI Facing page 58

Tables VIa, VIb Facing page 59

Table VII Facing page 63

Table VII a On page 63

Table VIII Facing page 65

Table VIlla On page 65

Table IX On page 67

Table X Facing page 70

Tables xa, Xb Facing page 7l

Tables XI, XI a On page 75

Table XII Facing page 79

Table XIII Facing page 81

Table XIII a On page 81

Table XIV Table XV Table XVI

LIST OF FIGURES.

Figure I

Figures IIA, IIB Figures III, IV Figure V

Figure VI

Figures VII, VIII, IX, X

(vrr)

Appendix Appendix Appendix

Facing page Facing page Facing page Facing page Facing page Appendix

Page VI( iii) VI(v) VI(vii)

34 39 47 67 69 VI(viii)