I know the IGF-1 is a compound that is deemed useless as a dermal but I cant remember where I learned that. It has something to do with the makeup of the compound and how it actually works. MR can probably give you more detail on that.
Heres one of the studies I found on Pubmed
link
The expression of insulin-like growth factor 1 in follicular dermal papillae correlates with therapeutic efficacy of finasteride in androgenetic alopecia.
Tang L, Bernardo O, Bolduc C, Lui H, Madani S, Shapiro J.
Division of Dermatology, The University of British Columbia, Vancouver Hospital, Canada.
BACKGROUND: It is generally believed that dihydrotestosterone is one of the pivotal mediators of hair loss in androgenetic alopecia (AGA). Finasteride, which blocks the conversion of testosterone to dihydrotestosterone, has now become an integral part of the current treatment approaches for male AGA. Several lines of evidence support the notion that dermal papilla (DP) cells represent the androgen target within the hair follicle. The specific molecular regulators modulated by androgens within hair follicles in the balding scalp are unknown. OBJECTIVE: The purpose of this study was to identify and quantify changes in expression of specific molecular hair growth regulators in DP of men with AGA treated with finasteride and correlate these findings to clinical efficacy. METHODS: Biopsy specimens were collected from 9 male patients from both the balding area and nonbalding occipital area before and after 4 months of finasteride therapy. DP were microdissected and total RNA was extracted from an equal number of DP from each biopsy specimen. The expression of various cytokines, including insulin-like growth factor (IGF)-1, was determined by reverse transcription polymerase chain reaction. The signals were detected by autoradiography. All 9 patients were given finasteride for 1 year and evaluated for efficacy at month 12. Efficacy was graded on a 7-point scale on the basis of comparison with initial baseline photography. RESULTS: IGF-1 was up-regulated by finasteride treatment in 4 of 9 patients. Among the patients with increased IGF-1 expression, 3 of them showed moderate clinical improvement after 12 months of treatment and another patient remained unchanged. In contrast, 3 patients with decreased IGF-1 expression in the balding scalp showed clinical worsening after 12 months. The other 2 patients without noticeable change in IGF-1 expression showed either slight improvement or no change in their hair condition. CONCLUSION: In a small uncontrolled study of 9 patients with AGA, an increased expression of IGF-1 messenger RNA levels in the DP was associated with patient response to finasteride.
PMID: 12894070 [PubMed - indexed for MEDLINE]
This one states that high levels of test along with IGF-1 have negative impacts on hair.
Hormones and hair patterning in men: a role for insulin-like growth factor 1?
Signorello LB, Wuu J, Hsieh C, Tzonou A, Trichopoulos D, Mantzoros CS.
Department of Epidemiology and Harvard Center for Cancer Prevention, Harvard School of Public Health, Boston, Massachusetts 02115, USA.
BACKGROUND: Androgens are important in hair growth and patterning, whereas growth hormone substitution enhances their effect in growth hormone-deficient men. No previous study has jointly evaluated the function of sex steroids, sex hormone-binding globulin (SHBG), and insulin-like growth factor (IGF-1) in determining hair patterning in men. OBJECTIVE: We assessed the relationship between circulating hormone measurements and both head and chest hair patterning in a sample of elderly men. METHODS: Fifty-one apparently healthy men older than 65 years of age were studied cross-sectionally. Head and chest hair patterning was assessed by a trained interviewer. Morning blood samples from all subjects were used for measurements of testosterone, estradiol, dehydroepiandrosterone sulfate, SHBG, and IGF-1. RESULTS: Results were obtained from logistic regression models, adjusting simultaneously for all the measured hormones and age. Men with higher levels of testosterone were more likely to have vertex baldness (odds ratio [OR] = 2.5, 95% confidence interval [CI: 0.9 to 7.8] per 194 ng/dL increment of testosterone). In addition, for each 59 ng/mL increase in IGF-1, the odds of having vertex baldness doubled (95% CI [1.0 to 4.6]). Those who were found to have higher circulating levels of SHBG were less likely to have dense hair on their chest (OR = 0.4, 95% CI [0.1 to 0.9] per 24 nmol/L increment in SHBG]). CONCLUSION: Testosterone, SHBG, and IGF-1 may be important in determining hair patterning in men.
PMID: 10025745 [PubMed - indexed for MEDLINE]
I also keep coming across studies that show that Minoxidil along with IGF-1 increases the effects of the Minoxidil. BUT!!!!
A couple other studies show that retinoic acid along with IGF-1 reduce the concentration of IGF action on DP (Dermal Papilla) available to stimulate hair elongation and maintenance of anagen phase.
MORE!
J Dermatol Sci. 1994 Jul;7 Suppl:S55-72. Related Articles, Links
Human hair growth in vitro: a model for the study of hair follicle biology.
Philpott MP, Sanders D, Westgate GE, Kealey T.
Department of Clinical Biochemistry, University of Cambridge, Addenbrookes Hospital, UK.
The factors that regulate hair follicle growth are still poorly understood. In vitro models may be useful in elucidating some aspects of hair follicle biology. We have developed an in vitro human hair growth model that enables us to maintain isolated human hair follicles for up to 10 days, during which time they continue to grow at an in vivo rate producing a keratinised hair fibre. We have shown that epidermal growth factor (EGF) in our system mimics the in vivo depilatory action of EGF in sheep, and suggest that this occurs as a result of EGF stimulating outer root sheath (ORS) cell proliferation which results in the disruption of normal mechanisms of cell-cell interaction in the hair follicle. We identify transforming growth factor-beta (TGF-beta) as a possible negative regulator of hair follicle growth and show that physiological levels of insulin-like growth factor-I (IGF-I) can support the same rates of hair follicle growth as supraphysiological levels of insulin. Furthermore, in the absence of insulin hair follicles show premature entry into a catagen-like state. This is prevented by physiological levels of IGF-I. Finally we demonstrate that the hair follicle is an aerobic glycolytic, glutaminolytic tissue and discuss the possible implications of this metabolism.
Publication Types:
* Review
* Review, Tutorial
PMID: 7999676 [PubMed - indexed for MEDLINE]
J Invest Dermatol. 1994 Jun;102(6):857-61. Related Articles, Links
Effects of insulin and insulin-like growth factors on cultured human hair follicles: IGF-I at physiologic concentrations is an important regulator of hair follicle growth in vitro.
Philpott MP, Sanders DA, Kealey T.
Department of Clinical Biochemistry, University of Cambridge, Addenbrookes Hospital, U.K.
Insulin stimulated hair follicle growth in a dose-dependent manner over the range of 0.01 to 100 micrograms/ml. Maximum rates of hair follicle growth were observed when follicles were maintained in medium containing 10 micrograms/ml insulin, which is supraphysiologic. Hair follicles maintained in the absence of insulin or at physiologic levels showed premature entry into a catagen-like state. Insulin-like growth factor (IGF)-I and -II had no significant effect on hair follicle growth when maintained in the presence of 10 micrograms/ml insulin. However, in the absence of insulin, both IGF-I (0.01-100 ng/ml) and IGF-II (0.01-100 ng/ml) stimulated hair follicle growth in a dose-dependent manner. IGF-I was more potent than either insulin or IGF-II, stimulating maximum rates of hair follicle growth at 10 ng/ml, whereas IGF-II gave maximum stimulation at 100 ng/ml. The rates of hair follicle growth stimulated by 10 ng/ml IGF-I were identical to those stimulated by 10 micrograms/ml insulin. IGF-II (100 ng/ml), however, was unable to stimulate hair follicle growth to the same extent as insulin. Both IGF-I (10 ng/ml) and IGF-II (100 ng/ml) were more potent than insulin at preventing hair follicles from entering into a catagen-like state. Growth hormone had no effect on hair follicle growth or morphology in the absence of insulin. These data suggest that in vitro IGF-I may be an important physiologic regulator of hair growth and possibly the hair growth cycle. Moreover, the removal of insulin from tissue culture medium may be a useful method of generating large numbers of catagen hair follicles for further in vitro studies.
PMID: 8006448 [PubMed - indexed for MEDLINE]
