The effects of bovine somatotropin on hair follicle activity and cashmere fibre growth in goats

1999 ◽  
Vol 50 (8) ◽  
pp. 1365 ◽  
Author(s):  
D. Villar ◽  
S. M. Rhind ◽  
S. R. McMillen ◽  
P. Dicks
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Hair Follicle ◽  
Bovine Somatotropin ◽  
Igf I ◽  
Fibre Growth ◽  
Cashmere Goats ◽  
The Mean ◽  
Secondary Fibre

The aim of this study was to determine the role of circulating growth hormone (GH) profiles in the cessation of secondary hair follicle activity and secondary fibre growth in goats during autumn/winter and to determine whether it is possible to extend the period of growth of this fibre by artificially increasing circulating concentrations of this hormone. Nine cashmere goats were each injected, weekly, with 50 mg of bovine somatotropin (bST; treated) in carrier oil, for a period of 5 months between late August and late January. Goats of a second group of 9 animals were injected with sesame oil and served as controls. Treated goats had significantly higher circulating concentrations of growth hormone (P< 0.001), insulin (P< 0.01), thyroxine (P< 0.001), and insulin-like growth factor-I (IGF-I; P< 0.001). Secondary fibre growth rate and liveweight gains were significantly (P< 0.05) higher in treated than control goats. The proportion of active secondary follicles was positively associated with circulating IGF- I concentrations in treated but not control goats. Follicle activity was not related to the profiles of any of the other hormones measured. The mean date of cessation of secondary fibre growth was not affected by treatment. It is concluded that treatment with bST stimulated the rate of secondary fibre growth but did not delay the time of cessation of this growth or the decline in follicle activity. It is further concluded that circulating hormone profiles do not directly control follicle activity and secondary fibre growth and moult and that their effects probably involve changes within the skin and/or hair follicle, possibly in hormone receptor populations, deiodinase enzyme activity, or growth factor synthesis.

An investigation of the role of thyroid hormones in the control of secondary fibre growth and moult in cashmere goats

1995 ◽  
Vol 1995 ◽  
pp. 104-104
Author(s):  
S.M. Rhind ◽  
S.R. McMillen
Keyword(s):  
Seasonal Variation ◽  
Thyroid Hormones ◽  
Hair Follicle ◽  
Seasonal Cycle ◽  
Reproductive Activity ◽  
Direct Role ◽  
Fibre Growth ◽  
Cashmere Goats ◽  
Secondary Fibre

The growth of a fine undercoat (cashmere) in goats is a seasonal phenomenon; growth generally begins during the autumn, continues into the winter and is followed by a moult in the spring. The endocrine mechanisms involved in the control of these processes are unclear but the thyroid hormones have been implicated in the control of fibre growth (Ferguson, Schenckel, Carter and Clarke, 1956; Lincoln, Klandorf and Anderson, 1980) and in the normal seasonal cycle of reproductive activity in sheep (Follett and Potts, 1990). However, it is not known whether or not the thyroid hormones have a role in the mediation of photoperiodic effects on secondary hair follicle activity in goats.Most of the metabolic activity of the thyroid hormones is thought to be attributable to triiodothyronine (T3) which is primarily derived from thyroxine (T4) by a process of monodeiodination. This process can be inhibited by treatment with methylthiouracil.The aim of this study was to suppress the synthesis of T3 and so to determine whether or not it has a direct role in the control of seasonal variation of secondary hair follicle activity and cashmere growth and moulting.

An investigation of the role of thyroid hormones in the control of secondary fibre growth and moult in cashmere goats

1995 ◽  
Vol 1995 ◽  
pp. 104-104
Author(s):  
S.M. Rhind ◽  
S.R. McMillen
Keyword(s):  
Seasonal Variation ◽  
Thyroid Hormones ◽  
Hair Follicle ◽  
Seasonal Cycle ◽  
Reproductive Activity ◽  
Direct Role ◽  
Fibre Growth ◽  
Cashmere Goats ◽  
Secondary Fibre

The growth of a fine undercoat (cashmere) in goats is a seasonal phenomenon; growth generally begins during the autumn, continues into the winter and is followed by a moult in the spring. The endocrine mechanisms involved in the control of these processes are unclear but the thyroid hormones have been implicated in the control of fibre growth (Ferguson, Schenckel, Carter and Clarke, 1956; Lincoln, Klandorf and Anderson, 1980) and in the normal seasonal cycle of reproductive activity in sheep (Follett and Potts, 1990). However, it is not known whether or not the thyroid hormones have a role in the mediation of photoperiodic effects on secondary hair follicle activity in goats.Most of the metabolic activity of the thyroid hormones is thought to be attributable to triiodothyronine (T3) which is primarily derived from thyroxine (T4) by a process of monodeiodination. This process can be inhibited by treatment with methylthiouracil.The aim of this study was to suppress the synthesis of T3 and so to determine whether or not it has a direct role in the control of seasonal variation of secondary hair follicle activity and cashmere growth and moulting.

Systemic metabolic effects of combined insulin-like growth factor–I and growth hormone therapy in patients who have sustained acute traumatic brain injury

2006 ◽  
Vol 105 (6) ◽  
pp. 843-852 ◽  
Author(s):  
Jimmi Hatton ◽  
Richard Kryscio ◽  
Melody Ryan ◽  
Linda Ott ◽  
Byron Young
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Treatment Group ◽  
Control Group ◽  
Insulin Like Growth Factor ◽  
Gh Therapy ◽  
Factor I ◽  
Igf I ◽  
The Mean ◽  
Growth Factor I

Object Hypermetabolism, hypercatabolism, refractory nitrogen wasting, hyperglycemia, and immunosuppression accompany traumatic brain injury (TBI). Pituitary dysfunction occurs, affecting growth hormone (GH) and plasma insulin-like growth factor–I (IGF-I) concentrations. The authors evaluated whether combination IGF-I/GH therapy improved metabolic and nutritional parameters after moderate to severe TBI. Methods The authors conducted a prospective, randomized, double-blind study comparing combination IGF-I/GH therapy and a placebo treatment. Ninety-seven patients with TBI were enrolled in the study within 72 hours of injury and were assigned to receive either combination IGF-I/GH therapy or placebo. All patients received concomitant nutritional support. Insulin-like growth factor–I was administered by continuous intravenous infusion (0.01 mg/kg/hr), and GH (0.05 mg/kg/day) was administered subcutaneously. Placebo control group patients received normal saline solution in place of both agents. Nutritional and metabolic monitoring continued throughout the 14-day treatment period. The two groups did not differ in energy expenditure, nutrient intake, or use of insulin treatment. The mean daily serum glucose concentration was higher in the treatment group (123 ± 24 mg/dl) than in the control group (104 ± 11 mg/dl) (p < 0.03). A positive nitrogen balance was achieved within the first 24 hours in the treatment group and remained positive in that group throughout the treatment period (p < 0.05). This pattern was not observed in the control group. Plasma IGF-I concentrations were above 350 ng/ml in the treatment group throughout the study period. Overall, the mean plasma IGF-I concentrations were 1003 ± 480.6 ng/ml in the treatment group and 192 ± 46.2 ng/ml in the control group (p < 0.01). Conclusions The combination of IGF-I and GH produced sustained improvement in metabolic and nutritional endpoints after moderate to severe acute TBI.

Body size parallels insulin-like growth factor I levels but not growth hormone secretory capacity

1984 ◽  
Vol 106 (4) ◽  
pp. 448-453 ◽  
Author(s):  
J. E. Eigenmann ◽  
D. F. Patterson ◽  
E. R. Froesch
Keyword(s):  
Growth Hormone ◽  
Body Size ◽  
Growth Factor ◽  
Indirect Evidence ◽  
Factor I ◽  
Igf I ◽  
The Mean ◽  
Growth Factor I ◽  
Secretory Capacity

Abstract. The relationships between body size, growth hormone (GH) secretory capacity and circulating insulinlike growth factor I (IGF I) levels were studied in genetically-determined subgroups of disparate size within one breed of dogs, the Poodle. Standard (large) Poodles exhibited six times the mean plasma IGF I concentration found in Toy Poodles. The mean IGF I level found in Standard Poodles significantly differed from the one found in Miniature and Toy Poodles (P < 0.001). The correlation between circulating IGF I levels and body size was found to be highly significant (P < 0.001; r = 0.88). All dogs secreted similar, normal amounts of GH in response to clonidine administration. The results show that body weight is correlated with IGF I levels rather than with the GH secretory capacity, thus providing indirect evidence for IGF I as an important in vivo growth-promoting principle.

Insulin-like growth factor I in the dog: a study in different dog breeds and in dogs with growth hormone elevation

1984 ◽  
Vol 105 (3) ◽  
pp. 294-301 ◽  
Author(s):  
J. E. Eigenmann ◽  
D. F. Patterson ◽  
J. Zapf ◽  
E. R. Froesch
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Gel Chromatography ◽  
Insulin Like Growth Factor ◽  
Significant Drop ◽  
Factor I ◽  
Igf I ◽  
The Mean ◽  
Growth Factor I ◽  
The One

Abstract. A radioimmunoassay (RIA) devised for the measurement of human insulin-like growth factor I (IGF I) was employed for the measurement of canine IGF I. Canine IGF I was extracted from plasma specimens by gel chromatography. Columns were eluted with 1 m acetic acid and the fractions representing the 55 to 85% bed volume were pooled, lyophilized and reconstituted with assay buffer. Serial dilutions of canine IGF I from both normal and acromegalic dogs when added to the RIA system gave a similar displacement pattern of human [125I]IGF I as the one obtained by the addition of unlabelled human IGF I. The dose-response curve obtained by canine IGF I paralleled the one obtained by human IGF I. Logit-log transformation and least squares fitting resulted in straight line fitting of the standard curve between 0.039 and 5 ng IGF I added per tube. The within-assay coefficient of variation (CV) was 16.7% and the between-assay CV was 21.8%. Plasma IGF I concentrations in normal dogs appeared to be a function of body size. The concentrations were 36 ± 27 ng/ml in Cocker Spaniels, 87 ± 33 ng/ml in Beagles, 117 ± 34 ng/ml in Keeshonds, and 280 ± 23 ng/ml in German Shepherds (mean ± sem). The mean IGF I level in a group of dogs with growth hormone (GH) elevation was 700 ± 90 ng/ml. Though this group of dogs comprised both small and large dogs, the mean IGF I level significantly differed from the one found in German Shepherds, the largest breed studied (P < 0.01). IGF I levels in dogs with GH elevation were similarly elevated in both dogs exhibiting acromegaly and dogs exhibiting GH-diabetes, but no signs of acromegaly. In dogs with GH elevation, drop in GH levels was associated with a significant drop in IGF I levels.

Skin deiodinase profiles and associated patterns of hair follicle activity in cashmere goats of contrasting genotypes

2004 ◽  
Vol 55 (4) ◽  
pp. 443 ◽  
Author(s):  
S. M. Rhind ◽  
C. E. Kyle
Keyword(s):  
Hair Follicle ◽  
Physiological State ◽  
Genotypic Differences ◽  
Type Ii ◽  
Long Day ◽  
Significant Difference ◽  
Igf I ◽  
Fibre Growth ◽  
Cashmere Goats ◽  
Skin Samples

The roles of skin deiodinase enzymes in the expression of genotypic differences in hair follicle activity and cashmere fibre growth and moult were studied in 9 Siberian (S) and 10 Scottish cashmere (SC) goats. The proportion of animals exhibiting cashmere growth was significantly greater in S than in SC goats in both late July (P < 0.001; early in the season of growth) and between January and April (P < 0.001; late in the season of growth), but there was no significant difference in the time of moult onset. Patterns of hair follicle activity exhibited similar seasonal differences, with secondary follicle activity being higher in S than in SC animals during the January–June period. Overall mean concentrations of IGF-I were lower (P < 0.01) in S than in SC animals and mean T4 concentrations were higher (P < 0.05) in S than in SC animals, but these differences were not related to genotypic differences in follicle activity or cashmere fibre growth. Mean concentrations of insulin, prolactin, and T3 did not differ with genotype. Between January and early April, mean prolactin concentrations were higher in S than in SC animals (P < 0.05). Monodeiodinase type II (MDII) activity in skin samples was highest (P < 0.001) during December and January (short day photoperiod) and was lower in S than in SC animals (P < 0.05) at these times. Mean monodeiodinase type III (MDIII) activity was highest during June and July (long day photoperiod). There was no difference between genotypes in the overall mean levels of deiodinase activity but, during January–March, when prolactin concentrations were higher in S than in SC goats, there was a higher rate of follicle activity and fibre growth in S goats. It is postulated that individual and genotype differences in hair follicle activity and cashmere growth are partially dependent on the pattern of expression of deiodinase enzymes in the skin. However, the actions of each enzyme are likely to depend on, among other factors, the absolute levels of expression of each type, the ratio of MDIII to MDII, the physiological state of the follicle, and the associated hormone profiles.

Growth hormone and insulin-like growth factor I in German Shepherd dwarf dogs

1984 ◽  
Vol 105 (3) ◽  
pp. 289-293 ◽  
Author(s):  
J. E. Eigenmann ◽  
S. Zanesco ◽  
U. Arnold ◽  
E. R. Froesch
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Gh Deficiency ◽  
Thyroid Stimulating Hormone ◽  
Insulin Like Growth Factor ◽  
German Shepherd ◽  
Factor I ◽  
Igf I ◽  
The Mean ◽  
Growth Factor I

Abstract. The roles of growth hormone (GH) and insulin-like growth factor I (IGF I) were studied in 9 German Shepherd dwarf dogs. GH deficiency was evidenced in all dogs by an absence of increase in GH levels in response to clonidine administration. While the mean IGF I concentration in normal adult German Shepherds was 280 ± 23 ng/ml and 345 ± 50 ng/ml in immature animals, the mean IGF I concentration in the dwarf dogs was 11 ± 2 ng/ml (mean ± sem, P < 0.001). In the affected animals, plasma thyroxine (T4) levels were only slightly subnormal and there was an increase in these levels in response to thyroid stimulating hormone (TSH) administration. The findings indicate 1) that dwarfism in German Shepherds is caused by primary GH-deficiency resulting in low circulating levels of IGF I and 2) that IGF I levels in the dog as in man are subject to control by GH.

scholarly journals Differential Diagnosis of the Short IGF-I-Deficient Child with Apparently Normal Growth Hormone Secretion

2021 ◽  
pp. 1-24
Author(s):  
Jan M. Wit ◽  
Sjoerd D. Joustra ◽  
Monique Losekoot ◽  
Hermine A. van Duyvenvoorde ◽  
Christiaan de Bruin
Keyword(s):  
Growth Hormone ◽  
Differential Diagnosis ◽  
Growth Hormone Secretion ◽  
Normal Growth ◽  
Stimulation Test ◽  
Healthy Children ◽  
Genetic Causes ◽  
Gh Secretion ◽  
Igf I

The current differential diagnosis for a short child with low insulin-like growth factor I (IGF-I) and a normal growth hormone (GH) peak in a GH stimulation test (GHST), after exclusion of acquired causes, includes the following disorders: (1) a decreased spontaneous GH secretion in contrast to a normal stimulated GH peak (“GH neurosecretory dysfunction,” GHND) and (2) genetic conditions with a normal GH sensitivity (e.g., pathogenic variants of <i>GH1</i> or <i>GHSR</i>) and (3) GH insensitivity (GHI). We present a critical appraisal of the concept of GHND and the role of 12- or 24-h GH profiles in the selection of children for GH treatment. The mean 24-h GH concentration in healthy children overlaps with that in those with GH deficiency, indicating that the previously proposed cutoff limit (3.0–3.2 μg/L) is too high. The main advantage of performing a GH profile is that it prevents about 20% of false-positive test results of the GHST, while it also detects a low spontaneous GH secretion in children who would be considered GH sufficient based on a stimulation test. However, due to a considerable burden for patients and the health budget, GH profiles are only used in few centres. Regarding genetic causes, there is good evidence of the existence of Kowarski syndrome (due to <i>GH1</i> variants) but less on the role of <i>GHSR</i> variants. Several genetic causes of (partial) GHI are known (<i>GHR</i>, <i>STAT5B</i>, <i>STAT3</i>, <i>IGF1</i>, <i>IGFALS</i> defects, and Noonan and 3M syndromes), some responding positively to GH therapy. In the final section, we speculate on hypothetical causes.

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