Havemeyer Foundati<strong>on</strong> M<strong>on</strong>ograph Series No. 3CHANGES OF PGFM, PROGESTERONE AND LHSECRETION PATTERNS IN RELATION TO CYCLELENGTH AFTER CERVICAL MANIPULATION IN MARESJ. Handler, M. Königsh<str<strong>on</strong>g>of</str<strong>on</strong>g>er, H. Kindahl*, H.-O. Hoppen † , J. E. Aurich andC. AurichUniversity <str<strong>on</strong>g>of</str<strong>on</strong>g> Veterinary Sciences, Vienna, Austria; *Swedish University <str<strong>on</strong>g>of</str<strong>on</strong>g> Agricultural Sciences, Uppsala,Sweden; † College <str<strong>on</strong>g>of</str<strong>on</strong>g> Veterinary Medicine, Hannover, GermanyINTRODUCTIONIn horses, early embry<strong>on</strong>ic loss after transcervicaltransfer <str<strong>on</strong>g>of</str<strong>on</strong>g> embryos is tremendous when comparedto o<str<strong>on</strong>g>the</str<strong>on</strong>g>r species. Better results have been obtainedafter surgical transfer. Endocrine changes causedby cervical manipulati<strong>on</strong> may be resp<strong>on</strong>sible forthis phenomen<strong>on</strong>.In n<strong>on</strong>-pregnant horse mares <str<strong>on</strong>g>the</str<strong>on</strong>g> effects <str<strong>on</strong>g>of</str<strong>on</strong>g>cervical manipulati<strong>on</strong> <strong>on</strong> cycle length werec<strong>on</strong>troversially discussed in previous studies(Hurtgen and Ganjam 1979; Betteridge et al.1985; Wilde et al. 1989). While Hurtgen andGanjam (1979) were able to shorten dioestrus bydigital manipulati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> cervix, Betteridge etal. (1985) as well as Wilde et al. (1989) could notfind any release <str<strong>on</strong>g>of</str<strong>on</strong>g> prostaglandins and influence<strong>on</strong> oestrous cycle after inserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> a transferca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter into <str<strong>on</strong>g>the</str<strong>on</strong>g> cervix. Kask et al. (1997)induced prostaglandin release and shortenedoestrous cycle length in individual mares byperforming sham embryo transfers, whileBetteridge et al. (1985) did not obtaincomparable resp<strong>on</strong>ses to this manipulati<strong>on</strong>. All<str<strong>on</strong>g>the</str<strong>on</strong>g>se c<strong>on</strong>flicting results might be caused by <str<strong>on</strong>g>the</str<strong>on</strong>g>use <str<strong>on</strong>g>of</str<strong>on</strong>g> different techniques <str<strong>on</strong>g>of</str<strong>on</strong>g> cervicalstimulati<strong>on</strong>.In <str<strong>on</strong>g>the</str<strong>on</strong>g> present study we tested <str<strong>on</strong>g>the</str<strong>on</strong>g> hypo<str<strong>on</strong>g>the</str<strong>on</strong>g>sisthat in n<strong>on</strong>-pregnant mares, a standardisedprocedure <str<strong>on</strong>g>of</str<strong>on</strong>g> cervical manipulati<strong>on</strong> and dilatati<strong>on</strong>causes an increase in prostaglandin release leadingto disturbances <str<strong>on</strong>g>of</str<strong>on</strong>g> luteal functi<strong>on</strong> and a subsequentdecrease in cycle length.MATERIALS AND METHODSMares (n=6) were c<strong>on</strong>trolled for cyclic activityduring 5 c<strong>on</strong>secutive oestrous cycles (oestrousbehaviour, transrectal palpati<strong>on</strong> and s<strong>on</strong>ographicevaluati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> ovaries and uterus). Daily bloodsamples were taken for determinati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> plasmaprogester<strong>on</strong>e and LH c<strong>on</strong>centrati<strong>on</strong>s. Progester<strong>on</strong>eas well as LH secreti<strong>on</strong> were calculated as areaunder <str<strong>on</strong>g>the</str<strong>on</strong>g> curve (AUC) for <str<strong>on</strong>g>the</str<strong>on</strong>g> time period fromDay 1–Day 18 <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> cycle (ovulati<strong>on</strong> = Day 0).During <str<strong>on</strong>g>the</str<strong>on</strong>g> sec<strong>on</strong>d, third and fourth cycle at Days5 and 7 after ovulati<strong>on</strong>, <str<strong>on</strong>g>the</str<strong>on</strong>g> following experimentswere performed in every mare at random order:1) Inserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> an embryo flushing ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter into <str<strong>on</strong>g>the</str<strong>on</strong>g>cervix via speculum; 2) Inserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ca<str<strong>on</strong>g>the</str<strong>on</strong>g>terTABLE 1: Oestrous cycle length, dioestrous length, maximal progester<strong>on</strong>e c<strong>on</strong>centrati<strong>on</strong>s and totalprogester<strong>on</strong>e release (AUC) in mares after inserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> a ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter into <str<strong>on</strong>g>the</str<strong>on</strong>g> cervix (inserti<strong>on</strong>), afterinserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter and dilatati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ballo<strong>on</strong> (dilatati<strong>on</strong>) and without treatment (c<strong>on</strong>trol)Treatment Cycle length Dioestrous length Max P4 P4 (AUC)d, mean ± sd d, mean ± sd ng/ml, mean ± sd ng/ml, mean ± sdC<strong>on</strong>trol 22.7 ± 2.1 a 18.8 ± 1.8 a 8.5 ± 1.1 a 83.1 ± 15.8 aInserti<strong>on</strong> 21.8 ± 2.8 17.2 ± 2.2 8.1 ± 1.8 76.6 ± 14.2Dilatati<strong>on</strong> 19.8 ± 1.2 b 16.3 ± 1.4 b 7.8 ± 1.4 b 70.6 ± 14.5 ba,b – different superscripts indicate significant differences (P
Equine Embryo Transfer6055C<strong>on</strong>trolInserti<strong>on</strong>Dilatati<strong>on</strong>50Plasma-PGFM (pmol/l)4540353025200 10 20 30 31 31.5 32 32.5 33 33.5 34 34.5 35 35.5 36 37 38 41 46 56 96MinFig 1: PGFM c<strong>on</strong>centrati<strong>on</strong> in blood plasma <str<strong>on</strong>g>of</str<strong>on</strong>g> mares after inserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> a ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter into <str<strong>on</strong>g>the</str<strong>on</strong>g> cervix (inserti<strong>on</strong>), afterinserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter and dilatati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ballo<strong>on</strong> (dilatati<strong>on</strong>) and without treatment (c<strong>on</strong>trol). Black barindicates time period <str<strong>on</strong>g>of</str<strong>on</strong>g> dilatati<strong>on</strong> and inserti<strong>on</strong>, respectively.and stepwise dilatati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ballo<strong>on</strong> to a size <str<strong>on</strong>g>of</str<strong>on</strong>g>4.5 cm in diameter; 3) No treatment (c<strong>on</strong>trol).Blood samples for determinati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> prostaglandinmetabolites (PGFM) were taken 30, 20, 10 minand immediately before inserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter,after inserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter and at 30 s intervalsduring dilatati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ballo<strong>on</strong>. Fur<str<strong>on</strong>g>the</str<strong>on</strong>g>r bloodsamples were taken 1, 2, 5, 20 and 60 min afterremoval <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter. Horm<strong>on</strong>e c<strong>on</strong>centrati<strong>on</strong>swere analysed by radioimmunoassay methods:progester<strong>on</strong>e (H<str<strong>on</strong>g>of</str<strong>on</strong>g>fmann et al. 1973), LH (Behrenset al. 1993) and PGFM (Granström and Kindahl1982).RESULTS AND DISCUSSIONIntracervical inserti<strong>on</strong> and dilatati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g>ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter caused significant changes inprogester<strong>on</strong>e levels, durati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> dioestrus andcycle length, respectively. Cycle length (inparen<str<strong>on</strong>g>the</str<strong>on</strong>g>ses dioestrous length) was 21.8 ± 2.8(17.2 ± 2.2) days in mares after inserti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g>ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter, 19.8 ± 1.2 (16.3 ± 1.4) after inserti<strong>on</strong> anddilatati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> ca<str<strong>on</strong>g>the</str<strong>on</strong>g>ter and 22.7 ± 2.1 (18.8 ±1.8) days in untreated mares (P
Change language