Activities of Glucose Metabolic Enzymes in Human Preantral Follicles: RESULTS(2)

The basal PK activity was almost undetectable in follicles cultured for 24 h without any hormonal stimulus; however, significant (p < 0.05) stimulation was noted in response to FSH and LH (Fig. 2). As with the PFK activity, FSH stimulation of PK activity for class 2 follicles was more pronounced (55-fold) than for class 1 follicles (6fold). Similarly, LH was more effective than FSH for class 1 in comparison to class 2 follicles (Fig. 2, A and B); however, the degree of LH stimulation for class 2 follicles was significantly (p < 0.5) greater than for class 1. Both EGF and IGF-I stimulated Pk activity almost similarly for class 1 and class 2 follicles (Fig. 2, A and B). proventil inhaler

TGF|31, on the other hand, augmented the enzyme activity 19-fold for class 1 as compared to class 2 follicles (8-fold; Fig. 2). Gonadotropins also significantly (p < 0.05) stimulated MDH activity for both class 1 and 2 follicles (Fig. 3). Whereas FSH stimulated MDH activity 170-fold for class 2 follicles (16 fold for class 1), the degree of LH action was almost similar for the two classes of follicles. The degree of MDH stimulation by EGF and IGF-I for class 1 and class 2 follicles, respectively, was almost similar; however, a 13-fold stimulation of MDH activity by TGFp1 for class 2 follicles was observed (Fig. 3B). TGFp1 also augmented MDH activity by 3-fold for class 1 follicles (Fig. 3A). LH and TGFp1 showed almost identical degrees of stimulation of MDH activity for class 2 follicles. Interestingly, IGF-I was more effective than EGF in inducing MDH activity for class 1 follicles.
Fig2Activities of Glucose Metabolic
FIG. 2. PK activity in human preantral follicles in class 1 (A) and class 2 (B) follicles cultured in vitro for 24 h in the presence or absence of gonadotropins and growth factors. Both gonadotropins and growth factors stimulated enzyme activity for class 1 and 2 follicles. The degree ofTGF^1 stimulation was greater for class 1 than for class 2 follicles; however, the TGFp1 effect on class 2 follicles was significant (p < 0.05). The reversal of FSH and LH effects between class 1 and 2 follicles was very prominent. Values with the same letter are significantly (p < 0.05) different from each other.

Fig3Activities of Glucose Metabolic
FIG. 3. MDH activity in human preantral follicles in class 1 (A) and class 2 (B) follicles exposed in vitro to gonadotropins and growth factors for 24 h. While both gonadotropins and all tested intraovarian growth factors significantly (p < 0.05) stimulated MDH activity for class 1 follicles, only FSH stimulation was 170-fold for class 2 follicles as compared to other treatment groups. Nevertheless, significant (p < 0.05) stimulation of MDH activity for class 2 follicles by LH and TGFp1 is evident. Values with same letter are significantly (p < 0.05) different from each other.

This entry was posted in Enzymes and tagged Enzymes, Follicles, Glucose Metabolic, Growth Factor, Hormone.