Cloprostenol, a synthetic analog of prostaglandin F2α induces functional regression in cultured luteal cells of felids†

In the present study, we investigated the effect of the synthetic analog of prostaglandin F2α (PGF2α)-cloprostenol-on cultured steroidogenic luteal cells of selected felid species over a 2-day culture period. The changes induced by cloprostenol were measured based on progesterone concentration and mRNA expression analysis of selected genes. Cloprostenol significantly reduced concentration of progesterone in cell culture medium of small luteal cells isolated from domestic cat corpora lutea (CL) at the development/maintenance stage (P < 0.05), but did not influence progesterone production in cultured cells from the regression stage. A decrease or complete silencing of progesterone production was also measured in cultured luteal cells of African lion (formation stage) and Javan leopard (development/maintenance stage). Gene-expression analysis by real-time PCR revealed that treatment with cloprostenol did not have an influence on expression of selected genes coding for enzymes of steroidogenesis (StAR, HSD3B, CYP11A1) or prostaglandin synthesis (PTGS2, PGES), nor did it effect hormone receptors (AR, ESR1, PGR, PTGER2), an anti-oxidative enzyme (SOD1) or factors of cell apoptosis (FAS, CASP3, TNFRSF1B, BCL2) over the studied period. Significant changes were measured only for expressions of luteinizing hormone (P < 0.05), prolactin (P < 0.05) and PGF2α receptors (P < 0.005) (LHCGR, PRLR, and PTGFR). The obtained results confirm that PGF2α/cloprostenol is a luteolytic agent in CL of felids and its impact on progesterone production depends on the developmental stage of the CL. Cloprostenol short-term treatment on luteal cells was associated only with functional but not structural changes related to luteal regression.

Responses to intra-luteal administration of cloprostenol in dairy cows

The aim of the study was to determine the luteolytic dose of cloprostenol administered directly into the corpus luteum (CL; intra-luteal treatment, ILT) in dairy cattle. Cows of two control groups were treated with 500 μg of cloprostenol (Estrumate®) intramuscularly (IM-500) or via ILT with 0.2 mL of physiological solution (ILT-0). Cows of four experimental groups were treated by ILT with cloprostenol in doses 5, 25, 50 and 100 μg (ILT-5, -25, -50 and -100 groups). Progesterone concentrations (P4) and size of CL were evaluated to assess luteolysis at 0, 0.5, 1, 2, 4, 8, 24 and 48 h or at 0, 24 and 48 h after ILT, respectively. Cows in the ILT-0 and -5 groups were unaffected by ILT. The P4 concentrations were less in cows of the IM-500, as well as ILT-25, -50 and -100 groups at 48 h subsequent to ILT. The size of the CL was less in cows of IM-500, as well as ILT-25, -50 and -100 groups at 48 h after ILT. There were P4 concentrations of about 1 ng/mL 48 h after ILT in cows of the IM-500, as well as ILT-50 and -100 groups. In conclusion, the cloprostenol dose of 50 μg administered intra-luteally is a luteolytic dose in cows.

Aglepristone and cloprostenol combination in the termination of late-term pregnancy in queens

OBJECTIVES

Termination rates for the highly recommended aglepristone (AGL) treatment are low in late-term pregnancy in queens. We studied the effects of an AGL and cloprostenol (CLO) combination in the termination of late-term pregnancy.

METHODS

Pregnant queens were assigned to two groups. Queens in the AGL group (n = 10) received AGL 10 mg/kg, twice, 24 h apart. Queens in the AGL-CLO group (n = 9) were additionally injected with a single dose of CLO (5 μg/kg) 24 h after the second dose of AGL. Progesterone, 17beta(β)-oestradiol, cortisol, oxytocin and prostaglandin F2alpha (PGF2α) metabolite were measured in sera obtained at days 0, 1 and 2, and on the day of abortion.

RESULTS

Average gestational age in both groups was similar (AGL 38.61 ± 0.91 days vs AGL-CLO 39.39 ± 1.35 days; P >0.05). Termination rates were 80% and 100% in the AGL and AGL-CLO groups, respectively (P <0.05). Fetal expulsion time was significantly longer (P <0.001) in the AGL group (96.9 ± 6 h) compared with the AGL-CLO group (69.8 ± 3.3 h). Duration of abortion was 19.8 ± 2.6 h and 12.6 ± 1.4 h in the AGL and AGL-CLO groups, respectively (P <0.05). Both treatments were well tolerated. Significantly (P <0.05) lower serum progesterone concentrations were observed in both groups at the day of abortion and concentrations in the AGL-CLO group (4.19 ± 0.80 ng/ml) were lower than in the AGL group (9.89 ± 2.21 ng/ml; P <0.05).

CONCLUSIONS AND RELEVANCE

AGL and CLO combination increases pregnancy termination rate in late-term pregnant queens. In addition, CLO contributes to a decrease in luteal function in AGL-treated late-term pregnant queens.

Fertility outcome after medically treated pyometra in dogs

Cystic endometrial hyperplasia-pyometra complex (CEH/P) is a challenge in canine reproduction. Present study aimed to assess fertility after medical treatment. One-hundred-seventy-four bitches affected by CEH/P received aglepristone on days 1, 2, 8, then every 7 days until blood progesterone < 1.2 ng/mL; cloprostenol was administered on days 3 to 5. Records were grouped according to bodyweight (BW): small (< 10 kg, n = 33), medium (10 ≥ BW < 25 kg, n = 44), large (25 ≥ BW < 40 kg, n = 52), and giant bitches (BW ≥ 40 kg, n = 45). Age; success rate; aglepristone treatments number; relapse, pregnancy rates; diagnosis-relapse, -first, -last litter intervals; litters number after treatment, and LS were analyzed by ANOVA. Overall age was 5.14 ± 1.75 years, without difference among groups. Treatment was 100% successful, without difference in treatments number (4.75 ± 1.18), relapse (15/174, 8.62%) and pregnancy (129/140 litters, 92.14%) rates, intervals diagnosis-relapse (409.63 ± 254.9 days) or -last litter (418.62 ± 129.03 days). The interval diagnosis-first litter was significantly shorter (163.52 ± 51.47 days) and longer (225.17 ± 90.97 days) in small and giant bitches, respectively. Overall, 1.47 ± 0.65 litters were born after treatment. Expected LS was achieved in each group, as shown by ΔLS (actual-expected LS by breed, overall -0.40 ± 1.62) without differences among groups. Concluding, CEH/P affects younger dogs than previously described. Relapses were rarer than previously reported. Medical treatment with aglepristone+cloprostenol is effective and safe, preserving subsequent fertility, as demonstrated by negligible changes in LS.

Stimulation of Bladder Acupoints by Cloprostenol for Treating Back Soreness in Athletic Horses

Twenty-five Thoroughbred jumper geldings suffered back soreness with poor performance, and 5 control horses were assessed by archived computer data, clinical examination, and laboratory analyses of complete blood picture, serum enzymes, and cortisol level, before and after cloprostenol-pharmacopuncture. The 25 diseased horses before therapy showed significant increases in aspartate aminotransferase and creatine phosphokinase with clinical pains scored mild in 15 horses, moderate in 9 horses, and severe in one horse, without changes in the hormonal and hematological data. After therapy, they responded by an increase of heart rate (57.8 ± 4.3 bpm), body temperature (38.5 ± 0.7°C), respiration rate (28.3 ± 2.1 bpm), and capillary refilling time (CRT) (1.0 ± 0.0). On the 2^nd day, a significant decrease in the mean levels of aspartate aminotransferase and creatine phosphokinase (P = 0.001) was detected, while on the 4^th day, they mimed the level of the 5 controls, and on the 6^th day, they showed a significant decrease (P = 0.002). The serum cortisol level showed a significant increase on the 6^th day of treatment (P = 0.013). The blood picture showed significant increases in red blood cells, mean corpuscular volume, platelets, white blood cells, hemoglobin, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, mean platelet volume, platelet distribution width, lymphocytes, plateletcrit, and large platelet concentration ratio (P < 0.05) and nonsignificant changes in hematocrit, granulocytes, and midocytes. The improved blood parameters, enzymes, hormones, and performance progress after cloprostenol-pharmacopuncture proved its effectiveness in treating back soreness in athletic horses.

Monitoring ovarian cycles, pregnancy and post-partum in captive marsh deer (Blastocerus dichotomus) by measuring fecal steroids

The marsh deer is an endangered species from the marshlands of central South America. This study aimed to characterize certain aspects of the reproductive physiology of marsh deer hinds, including the duration and fecal progestins profile of the estrous cycle, pregnancy and post-partum periods, and evaluate the effect of cloprostenol administration on this species. The experimental group consisted of six females and one fertile male marsh deer. During monitoring of the estrous cycle, the fresh fecal samples were collected daily and, during pregnancy, they were collected twice weekly. The hormonal profile obtained from daily fecal samples indicated that the mean duration of the estrous cycle was 21.3 ± 1.3 days (6.4 days inter-luteal phase and 14.8 days luteal phase; n = 16 estrous cycles). The mean concentration of fecal progestins in the inter-luteal phase was 834 ± 311 ng g^-1, in the luteal phase was 3979 ± 1611 ng g^-1, value between them was 1457 ng g^-1. No significant difference in fecal estrogen concentrations was determined during the estrous cycle. The corpora luteum was not responsive to cloprostenol until Day 6 of the estrous cycle, the period previously described as the inter-luteal phase. Half the females became pregnant following treatment with cloprostenol and two others were fertilized in their natural estrous cycle. Four females delivered fawns, and the mean duration of pregnancy was 253 ± 4 days. Fecal progestin concentrations were similar to those of the estrous cycle during the first 11 weeks of pregnancy and increased significantly ( > 15250 ng g^-1) thereafter, providing a presumptive diagnosis guideline. Within 60 days of post-partum analyses, 75% of the deer exhibited behavioural estrus and/or ovarian activity. This study generated a broader understanding of the marsh deer species concerning the production of consistent data related to its reproduction. This knowledge can be used to assist the reproductive management of this species and, consequently, to promote its conservation.

Reproductive responses of dairy cows with ovarian cysts to simultaneous human chorionic gonadotropin or gonadotropin-releasing hormone and cloprostenol compared to gonadotropin-releasing hormone alone treatment

Aim:

Bovine ovarian cysts are a common cause of economic loss in modern dairy herds. The objective of the present study was to evaluate the reproductive responses to three protocols using hCG, GnRH and cloprostenol when the definite diagnosis of the type of ovarian cyst is/is not possible in dairy cows.

Materials and Methods:

A total of 144 lactating dairy cows with ovarian cysts were divided into three groups. At diagnosis (Day 0), cows in Group 1 (the conventional method, n=47) were injected with 0.02 mg of a GnRH analogue i.m. (Buserelin); cows in Group 2 (n=47) were intramuscularly treated with 0.02 mg Buserelin plus 500 µg cloprostenol; and cows in Group 3 (n=50) were intramuscularly treated with 1500 IU hCG plus 500 µg cloprostenol. All cows received 500 µg cloprostenol intramuscularly on Day 10.

Results:

No statistically significant differences were found in the recovery time, interval to conception, conception rate at first AI, and pregnancy rates by Days 70 and 100 after treatment among the three groups.

Conclusions:

Simultaneous treatment of ovarian cysts with hCG or GnRH and cloprostenol appeared to have no advantage over the conventional method, GnRH alone, in dairy cows. Furthermore, hCG and GnRH have an equal therapeutic effect in cows with ovarian cysts.

Induction of Parturition in the Cow using Cloprostenol and Dexamethasone in Combination

Two experiments were designed to test the hypothesis that induction of parturition in the cow would be more predictable with the simultaneous use of a combination of cloprostenol and dexamethasone than with either hormone used alone.In experiment I all 19 beef cows treated with 500 mug cloprostenol and 25 mg dexamethasone in combination calved within 72 hours whereas dexamethasone (n = 19) or cloprostenol (n = 16) treatments alone each resulted in two induction failures. In those cows successfully induced, the mean interval from treatment to birth was 34.6 +/- 1.4 hours for the cloprostenol plus dexamethasone group, 43.3 +/- 2.4 hours for the dexamethasone group and 44.9 +/- 2.1 hours for the cloprostenol group. Control cows (n = 15) did not calve during the first 72 hours after treatment with saline. The incidence of retained placenta ranged from 19 to 53% in induced groups whereas placentae were not retained by cows in the control group.In experiment II all 30 beef cows in the cloprostenol plus dexamethasone group calved within the 72 hour limit, with a mean interval of 39.1 +/- 1.0 hours. Twenty-six of 31 cows calved within 72 hours with a mean interval of 51.9 +/- 3.4 hours after a single injection of cloprostenol and 29 of 33 cows calved within 72 hours with a mean interval of 52.6 +/- 3.3 hours after two injections of cloprostenol, 12 hours apart. Five of 34 control cows calved within 72 hours of time of treatment. The incidence of retained placenta was again high in induced cows. Results indicate that the simultaneous administration of cloprostenol and dexamethasone does constitute a safe, reliable and effective method of inducing parturition in the cow.

Effect of dosage of cloprostenol on induction of farrowing and body temperature of sows

In an experiment involving 161 farrowings, cloprostenol was injected on day 112 or 113 of gestation at the recommended dosage (175 mug) or a lower dosage (125 mug). Cloprostenol treatment did not result in abnormally high body temperatures of sows at parturition. Farrowing began within 29 hours of injection in 94% and 88% of the sows treated with 175 mug and 125 mug cloprostenol respectively, as compared to 15% of saline-injected controls. The duration of farrowing and number stillborn were not affected by treatment. Sows farrowing within 19 hours of treatment tended to have a large number of piglets and a higher body temperature postpartum.