Prolactin in the Horse: Historical Perspective, Actions and Reactions, and Its Role in Reproduction

Thompson, Donald L.; Oberhaus, E.L.

doi:10.1016/j.jevs.2015.03.199

Cited by 16 publications

(10 citation statements)

References 85 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our experiment, mares of a primitive breed were used. Prolactin concentrations are reported to be higher during the summer than in winter (Thompson and Oberhaus, 2015). Compared to our study, results from experiments carried out during the summer (Chavatte-Palmer et al, 2002) have shown that sulpiride has less effect when PRL concentration is high, in contrast to individual predisposition (Gentry et al, 2002).…”

Section: Discussioncontrasting

confidence: 82%

Influence of sulpiride treatment on the level of prolactin and immunoglobulins in the peripheral blood of mares during the postpartum period

Migdał

Zagrajczuk

et al. 2017

Acta Veterinaria Hungarica

View full text Add to dashboard Cite

The aim of this study was to determine the effect of increased levels of prolactin (PRL) on the concentration of immunoglobulins in the blood, colostrum and milk of mares. The study was conducted on 12 mares of the Polish Pony breed (6 in the control and 6 in the experimental group). To induce hyperprolactinaemia in mares of the experimental group, 750 mg sulpiride was administered orally once a day. The initial PRL concentration was 52.22 ± 11.21 ng/ml in the control group and 49.39 ± 10.12 ng/ml in the experimental group. In the subsequent days, the concentration of PRL dynamically changed. Statistical analysis showed highly significant differences (P < 0.01) between the groups. The concentration of immunoglobulins in the blood plasma was at the same level during the experimental period (32.97-29.08 mg/ml in the experimental group and 28.60-18.11 mg/ml in the control group). Statistical analysis showed highly significant differences between the groups in blood plasma immunoglobulin level (P < 0.01). The highest immunoglobulin concentration was obtained within 12 h after parturition in the control and the experimental group (23.49 ± 2.12 mg/ml and 26.94 ±1.72 mg/ml, respectively). The lowest values were obtained on day 12 after parturition in the experimental group (10.15 mg/ml ± 1.47 mg/ml) and on day 7 after parturition in the control group (14.30 mg/ml ± 2.48 mg/ml). In conclusion, this study did not provide evidence that the lactogenic hormone prolactin is involved in the transfer of immunoglobulins into the colostrum in horses.

show abstract

Section: Discussioncontrasting

confidence: 82%

Influence of sulpiride treatment on the level of prolactin and immunoglobulins in the peripheral blood of mares during the postpartum period

Migdał

Zagrajczuk

et al. 2017

Acta Veterinaria Hungarica

View full text Add to dashboard Cite

show abstract

“…Thompson and Oberhaus [4] pointed out in their 2015 review of prolactin research in horses that a special relationship exists between estradiol stimulation of the adenohypophysis and the subsequent secretion of prolactin. Specifically, estradiol pretreatment of mares or geldings greatly enhances the prolactin response to either sulpiride or domperidone (i.e., dopaminergic antagonism), whereas other stimuli for prolactin release (e.g., TRH injection, exercise, PGF2α injection) do not synergize in the same way with estradiol [19].…”

Section: Discussionmentioning

confidence: 99%

“…Prolactin is one of several hormones that are rapidly released in response to acute stressors (brief exercise, twitching, physical excitement) in horses [1][2][3]. Hypothalamic dopamine from the tuberoinfundibular neurons is the main known regulator of prolactin secretion in most, if not all, mammals, including the horse, and interruption of this dopaminergic input to the adenohypophysis via dopaminergic receptor antagonists, such as sulpiride or domperidone, results in an immediate release of prolactin into the peripheral blood [reviewed by [4]]. Whether the prolactin response to stressors in the horse is caused by an interruption (reduction, cessation?)…”

Section: Introductionmentioning

confidence: 99%

Responses of Adenohypophyseal Hormones to Substance P Administration in Geldings: Comparison to Responses After Brief Exercise and Sulpiride Administration

Thompson

Valencia

Oberhaus

2016

Journal of Equine Veterinary Science

Self Cite

View full text Add to dashboard Cite

Nine adult geldings were used in three experiments to study the possible role of substance P in the prolactin responses to non-dopaminergic stimuli. Experiment 1 was performed as an incomplete Latin square design to determine the secretory responses of prolactin, growth hormone (GH), adrenocorticotropic hormone (ACTH), thyroid stimulating hormone (TSH), luteinizing hormone (LH) and follicle stimulating hormone (FSH) to intravenous administration of substance P. Doses tested and compared to no peptide (0 dose, control) were 62, 125, 250, and 500 ug of substance P. The three highest doses of peptide caused an immediate rise in heart rate, sweating, salivation, rhinorrhea, stretching of hind legs, and defecation. The lowest dose (62 ug) caused minor sweating, some rhinorrhea, and a rise in heart rate. Recovery from these physical responses was complete in approximately 30 min. All doses of substance P caused an immediate rise (P < 0.01) in plasma prolactin concentrations, with the three highest doses producing similar responses, and the 62 ug dose producing a minimal response (P < 0.05). Concentrations of ACTH (P < 0.01) and GH (P = 0.05) also increased after substance P administration; concentrations of LH, FSH, and TSH were unaffected. Experiment 2 compared the effects of brief exercise on hormonal characteristics. Two minutes of trotting increased (P < 0.01) plasma concentrations of GH, ACTH, and prolactin, as well as LH (P = 0.055). Experiment 3 determined the relative responses of prolactin to a fixed dose of sulpiride (0.1 mg/kg of body weight). In general, the prolactin responses to substance P were similar to those after exercise, which were both generally less than after sulpiride. These data are consistent with a possible role of substance P in the prolactin response to stressful stimuli.

show abstract

“…Increased PRL concentrations due to lack of stimulation of the DA receptors in the lactotroposes cause a self-regulating feedback loop to the tuberous-infundibular DA neurons. These cells are activated to produce more DA, resulting in a reduction in prolactin secretion [18]. Melanotrophs of the pituitary Physiology and Metabolic Anomalies of Dopamine in Horses: A Review http://dx.doi.org/10.5772/intechopen.78569…”

Section: Endocrine Systemmentioning

confidence: 99%

Physiology and Metabolic Anomalies of Dopamine in Horses: A Review

Ambrojo¹,

Poggi²,

Corzano³

2018

Dopamine - Health and Disease

View full text Add to dashboard Cite

Dopamine (DA) is an important endogenous catecholamine that exerts generalized effects on both neuronal (as a neurotransmitter) and non-neuronal tissues (as an autocrine or paracrine agent). In the central nervous system (CNS), DA binds to specific membrane receptors present in neurons and plays a key role in the control of motor activity, learning, cognition, affectivity and attention. Horses can also present with hyper-and hypodopaminergic conditions, including stereotypic behaviors and pituitary pars intermedia dysfunction and Parkinsonian's syndrome, respectively. DA biosynthesis also occurs in peripheral tissues, and receptors in various organs such as the kidney, pancreas, lungs and blood vessels outside the CNS have been detected. DA emulates the actions related to the sympathetic nervous system (SNS), promoting the increase in heart rate, blood pressure, electrolyte balance and gastrointestinal (GI) motility. In fact, GI alterations in dopaminergic transmission have been directly or indirectly related to hypomotility and/ or postoperative ileus (POI). On the other hand, there are physiological factors, such as breed, age, exercise and reproductive status that modify DA concentrations. In reproduction, the administration of DA antagonists in the middle/end of the spring and anestrus transition period advances the first ovulation of the year in mares. This chapter offers a brief description of the importance of DA as a neurotransmitter and peripheral hormone. Special attention is paid to: (1) functional alterations that occur in the brain and GI tract in various diseases and (2) current therapy to correct alterations in DA systems.

show abstract

Prolactin in the Horse: Historical Perspective, Actions and Reactions, and Its Role in Reproduction

Cited by 16 publications

References 85 publications

Influence of sulpiride treatment on the level of prolactin and immunoglobulins in the peripheral blood of mares during the postpartum period

Influence of sulpiride treatment on the level of prolactin and immunoglobulins in the peripheral blood of mares during the postpartum period

Responses of Adenohypophyseal Hormones to Substance P Administration in Geldings: Comparison to Responses After Brief Exercise and Sulpiride Administration

Physiology and Metabolic Anomalies of Dopamine in Horses: A Review

Contact Info

Product

Resources

About